Book A: Architecture and General Requirements

© 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. EMV ® Contactless Specifications for Payment Systems Book A Architecture and General Requirements Version 2.12 June 2026 EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 2 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. Legal Notice The EMV ® Specifications are provided “AS IS” without warranties of any kind, and EMVCo neither assumes nor accepts any liability for any errors or omissions contained in these Specifications. EMVCO DISCLAIMS ALL REPRESENTATIONS AND WARRANTIES, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON - INFRINGEMENT, AS TO THESE SPECIFICATIONS. EMVCo makes no representations or warranties with respect to intellectual property rights of any third parties in or in relation to the Specifications. EMVCo undertakes no responsibility to determine whether any implementation of the EMV Specifications may violate, infringe, or otherwise exercise the patent, copyright, trademark, trade secret, know-how, or other intellectual property rights of third parties, and thus any person who implements any part of the EMV Specifications should consult an intellectual property attorney before any such implementation. Without limiting the foregoing, the Specifications may provide for the use of public key encryption and other technology, which may be the subject matter of patents in several countries. Any party seeking to implement these Specifications is solely responsible for determining whether its activities require a license to any such technology, including for patents on public key encryption technology. EMVCo shall not be liable under any theory for any party’s infringement of any intellectual property rights in connection with the EMV Specifications. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 3 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. Revision Log – Version 2.12 This section outlines the notable updates that have been made to this specification since the publication of the EMV Contactless Specifications for Payment Systems, Book A Architecture and General Requirements, Version 2.11. Incorporated changes described in the following Specification Bulletin: Specification Bulletin no. 326: Book A Updates Minor editorial changes EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 4 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. 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Contents 1 Scope .......................................................................................................................... 11 1.1 Audience.............................................................................................................. 11 1.2 Overview .............................................................................................................. 12 2 References .................................................................................................................. 13 2.1 Volumes of the Contactless Specifications ........................................................... 13 2.2 EMV Documents .................................................................................................. 14 2.3 ISO Standards ..................................................................................................... 14 3 Conventions ................................................................................................................ 15 3.1 Requirement Numbering ...................................................................................... 15 3.2 Data Element Formats ......................................................................................... 15 4 Terminology ................................................................................................................ 17 4.1 Card ..................................................................................................................... 17 4.2 Transaction .......................................................................................................... 18 4.3 POS System ........................................................................................................ 19 4.4 Entry Point ........................................................................................................... 20 4.5 Kernel .................................................................................................................. 20 4.6 Outcome .............................................................................................................. 20 5 POS System Architecture........................................................................................... 21 5.1 POS System Descriptive Model ........................................................................... 21 5.2 Terminal and Reader Responsibilities .................................................................. 23 5.3 Logical Architecture ............................................................................................. 24 5.4 Operating Modes ................................................................................................. 25 5.5 POS System Functions ........................................................................................ 26 5.5.1 Non-interference with Contact Chip Interface ............................................ 26 5.5.2 No Overlapping Transactions ................................................................... 27 EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 5 / 115 © 2011-2026 EMVCo, LLC. 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EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.5.3 Cancellation ............................................................................................. 27 5.5.4 Field Management .................................................................................... 28 5.5.5 Displaying Amount.................................................................................... 28 5.5.6 Transaction Disposition ............................................................................ 28 5.5.7 Receipts ................................................................................................... 29 5.5.8 Cardholder Verification ............................................................................. 29 5.6 POS System Configuration .................................................................................. 31 5.6.1 POS System Country and Currency Codes .............................................. 31 5.6.2 POS System Configuration for Starting a Transaction ............................... 32 5.6.3 POS System Configuration for Acceptance Environment .......................... 32 5.6.4 POS System Configuration for Type of Transaction .................................. 33 5.6.5 Kernel and Entry Point Configuration Data................................................ 34 5.7 Transaction Data.................................................................................................. 35 5.8 Entry Point Processing ......................................................................................... 38 5.8.1 Starting Conditions ................................................................................... 38 5.8.2 Application Selection and Kernel Activation .............................................. 39 5.8.3 User Interface Request ............................................................................. 40 5.9 Kernel Processing ................................................................................................ 41 5.9.1 User Interface Request ............................................................................. 41 5.9.2 Processing Data Exchange....................................................................... 41 5.9.3 CVM Selection and Cardholder Verification .............................................. 42 6 Outcomes and Parameters......................................................................................... 43 6.1 Outcomes ............................................................................................................ 43 6.2 Outcome Parameters ........................................................................................... 48 6.3 Outcome Processing ............................................................................................ 54 7 User Interaction Overview .......................................................................................... 61 7.1 User Interface Request ........................................................................................ 62 7.2 Messaging and Status Display ............................................................................. 64 7.3 Amount Display and Entry .................................................................................... 65 EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 6 / 115 © 2011-2026 EMVCo, LLC. 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EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 8 POS System Requirements ........................................................................................ 66 9 User Interface Recommendations ............................................................................. 74 9.1 User Interface Hardware ...................................................................................... 74 9.1.1 Visual Indication ....................................................................................... 74 9.1.2 Audio Indication ........................................................................................ 75 9.2 Contactless Transaction Status (User) ................................................................. 76 9.3 User Interface Guidelines ..................................................................................... 78 9.3.1 Common User Interface Guidelines .......................................................... 79 9.3.2 Option 1 for Card Read Successfully/Processing Error ............................. 80 9.3.3 Option 2 for Card Read Successfully/Processing Error ............................. 84 9.4 User Interface Standard Messages ...................................................................... 88 10 Performance Requirements ....................................................................................... 92 10.1 Card in Field ........................................................................................................ 92 10.2 Allocation of Tariffs .............................................................................................. 93 10.3 Transaction Disposition ........................................................................................ 94 10.3.1 Offline ....................................................................................................... 94 10.3.2 Online ....................................................................................................... 95 10.4 Reference Cards .................................................................................................. 96 Annex A Data Elements for the Data Record and Discretionary Data........................ 97 Annex B Guidance on Outcome and Parameter Setting ............................................. 98 B.1 Approved ............................................................................................................. 99 B.2 Approved (with balance) .................................................................................... 100 B.3 Declined............................................................................................................. 101 B.4 Try Another Interface ......................................................................................... 102 B.5 Online Request .................................................................................................. 103 B.6 Online Request (for “Two Presentments”) .......................................................... 104 B.7 Online Request (for “Present and Hold”) ............................................................ 105 B.8 Request Online PIN ........................................................................................... 106 EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 7 / 115 © 2011-2026 EMVCo, LLC. 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B.9 Try Again ........................................................................................................... 107 B.10 Select Next ........................................................................................................ 108 B.11 End Application .................................................................................................. 108 B.12 End Application (with restart) ............................................................................. 109 Annex C Glossary ....................................................................................................... 110 EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 8 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. Figures Figure 5-1: POS System Descriptive Model ....................................................................... 22 Figure 5-2: Logical Architecture ......................................................................................... 24 Figure 9-1: Success Tone.................................................................................................. 75 Figure 9-2: Alert Tone ........................................................................................................ 75 Figure 10-1: Tariff Allocation for Transaction Timing .......................................................... 93 EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 9 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. 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Tables Table 5-1: Example Combination Table per Transaction Type ........................................... 33 Table 5-2: Entry Point Configuration Data per Combination ............................................... 34 Table 5-3: Entry Point Pre-Processing Indicators ............................................................... 35 Table 5-4: Terminal Transaction Qualifiers ........................................................................ 36 Table 5-5: Example Transaction-specific Data Elements ................................................... 37 Table 5-6: Type of Transaction .......................................................................................... 37 Table 6-1: Outcomes ......................................................................................................... 44 Table 6-2: Outcome Parameters ........................................................................................ 49 Table 6-3: First Final Outcome .......................................................................................... 54 Table 6-4: Second Final Outcome (Following an Online Request) ..................................... 57 Table 6-5: Third Final Outcome (Following a Request Online PIN) .................................... 60 Table 7-1: User Interface Request Data............................................................................. 62 Table 9-1: Contactless Transaction Status ........................................................................ 76 Table 9-2: Common User Interface Actions ....................................................................... 79 Table 9-3: User Interface Actions for Option 1 ................................................................... 80 Table 9-4: User Interface Actions for Option 2 ................................................................... 84 Table 9-5: User Interface Standard Messages ................................................................... 88 Table A.1: Kernel Data Record and Discretionary Data Reference .................................... 97 EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 10 / 115 © 2011-2026 EMVCo, LLC. 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Requirements Requirements – Configurations .......................................................................................... 66 Requirements – Entry of Amount ........................................................................................ 66 Requirements – New Transaction Preparation and Start .................................................... 67 Requirements – Unpredictable Number .............................................................................. 68 Requirements – RFU Bits and Bytes .................................................................................. 68 Requirements – Multiple Interfaces..................................................................................... 69 Requirements – Processing Data Exchange Request ......................................................... 70 Requirements – User Interface Request ............................................................................. 70 Requirements – Final Outcome Processing ........................................................................ 71 Requirements – Online Response – Restart ....................................................................... 72 Requirements – End Application – Restart ......................................................................... 73 Requirements – Request Online PIN – Restart ................................................................... 73 Requirements – Reader Tariff............................................................................................. 94 Requirements – Offline Transaction Disposition ................................................................. 94 Requirements – Online Transaction Disposition ................................................................. 95 EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 11 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 1 Scope With the goal of realising universal acceptance of contactless cards in an international interchange environment, EMVCo has developed a design for contactless payments that is compatible with existing payment system solutions, whilst offering the opportunity for the eventual development of a common EMV contactless acceptance solution. The design defines a generalised POS System environment that includes: • reader functionality, • terminal functionality, • Entry Point software that performs the initial analysis of a contactless transaction and invokes appropriate kernel software, and • several kernels, each of which provides processing appropriate to certain contactless transactions. This specification (Book A) describes the overall architecture, plus requirements for general features not specific to Entry Point or individual kernels. The other specifications in the suite, listed in section 2.1, describe Entry Point, the kernels, and the communication protocol. 1.1 Audience This specification is intended for use by manufacturers of readers and terminals. It may also be of interest to manufacturers of contactless cards and to financial institution staff responsible for implementing financial applications in contactless cards. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 12 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 1.2 Overview This volume includes the following chapters and annexes. Chapter 1 contains general information that helps the reader understand and use this specification. Chapter 2 lists related specifications and standards. Chapter 3 describes conventions used in this specification. Chapter 4 defines key terms used throughout the specifications, including card, transaction, POS System, Entry Point, kernel, and Outcome. Chapter 5 describes the architecture of the POS System discussed throughout the specifications. Chapter 6 describes all Outcomes and associated parameters. Chapter 7 provides on overview of user interaction. Chapter 8 defines POS System requirements. Chapter 9 provides recommendations for the user interface, including the use of visual and audio indications of the transaction status. Chapter 10 outlines performance requirements. Annex A provides an overview of the data elements used in the EMV Contactless Specifications for Payment Systems. Annex B provides guidance on Outcome and parameter setting. Annex C is a glossary of terms and abbreviations used in this specification. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 13 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 2 References The following specifications and standards contain provisions that are referenced in this specification. The latest version shall apply unless a publication date is explicitly stated. If any provision or definition in this specification differs from those in the standards listed in section 2.3, the provision or definition herein shall take precedence. 2.1 Volumes of the Contactless Specifications This specification is part of an eleven-volume set: Book A: Architecture and General Requirements Book B: Entry Point Specification Book C-2: Kernel 2 Specification Book C-3: Kernel 3 Specification Book C-4: Kernel 4 Specification Book C-5: Kernel 5 Specification Book C-6: Kernel 6 Specification Book C-7: Kernel 7 Specification Book C-8: Kernel 8 Specification Book E: Security and Key Management Level 1 Specifications for Payment Systems, EMV Contactless Interface Specification EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 14 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 2.2 EMV Documents EMV documents are available on the EMVCo website: http://www.emvco.com/ EMV Integrated Circuit Card Specifications for Payment Systems, Version 4.4, October 2022, including the following and all applicable Specification Bulletins: [EMV Book 1] EMV Integrated Circuit Card Specifications for Payment Systems, Book 1, Application Independent ICC to Terminal Interface Requirements [EMV Book 2] EMV Integrated Circuit Card Specifications for Payment Systems, Book 2, Security and Key Management [EMV Book 3] EMV Integrated Circuit Card Specifications for Payment Systems, Book 3, Application Specification [EMV Book 4] EMV Integrated Circuit Card Specifications for Payment Systems, Book 4, Cardholder, Attendant, and Acquirer Interface Requirements 2.3 ISO Standards ISO 639-1 Codes for the representation of names of languages – Part 1: Alpha-2 Code. Note: This standard is updated continuously by ISO. Additions/changes to ISO 639-1:1988: Codes for the Representation of Names of Languages are available on: http://www.loc.gov/standards/iso639-2/php/code_changes.php ISO 4217 Codes for the representation of currencies and funds. ISO 14443-3 Identification cards – Contactless integrated circuit(s) cards – Proximity cards – Part 3: Initialization and anticollision ISO/IEC 8859 Information Processing – 8-bit Single-Byte Coded Graphic Character Sets. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 15 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 3 Conventions This specification uses the following conventions. '0' to '9' and 'A' to 'F' 16 hexadecimal characters nb, nnb, nnnb, ... Binary values xx Any value proprietary Not defined in this specification and/or outside the scope of this specification may Denotes an optional feature shall Denotes a mandatory requirement should Denotes a recommendation 3.1 Requirement Numbering Requirements in this specification are uniquely numbered with a four-part numeric identifier appearing next to each requirement. A requirement may have different numbers in different versions of the specification. Hence, all references to a requirement must include the version of the specification as well as the requirement’s number. 3.2 Data Element Formats The EMV Contactless Specifications for Payment Systems use the following data element formats. A Alphabetic data elements contain a single character per byte. The permitted characters are alphabetic only (a to z and A to Z, upper and lower case). an Alphanumeric data elements contain a single character per byte. The permitted characters are alphabetic (a to z and A to Z, upper and lower case) and numeric (0 to 9). EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 16 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. ans Alphanumeric Special data elements contain a single character per byte. The permitted characters and their coding are shown in the Common Character Set table in [EMV Book 4] Annex B. There is one exception: The permitted characters for Application Preferred Name are the non-control characters defined in the ISO/IEC 8859 part designated in the Issuer Code Table Index associated with the Application Preferred Name. b These data elements consist of either unsigned binary numbers or bit combinations that are defined elsewhere. Binary example: The Application Transaction Counter (ATC) is defined as “b” with a length of two bytes. An ATC value of 19 is stored as Hex '00 13'. Bit combination example: Processing Options Data Object List (PDOL) is defined as “b” with the format shown in [EMV Book 3] section 5.4. cn Compressed numeric data elements consist of two numeric digits (having values in the range Hex '0'–'9') per byte. These data elements are left-justified and padded with trailing hexadecimal 'F's. Example: The Application Primary Account Number (PAN) is defined as “cn” with a length of up to ten bytes. A value of 1234567890123 may be stored in the Application PAN as Hex '12 34 56 78 90 12 3F FF' with a length of 8. n Numeric data elements consist of two numeric digits (having values in the range Hex '0'–'9') per byte. These digits are right-justified and padded with leading hexadecimal zeroes. Other specifications sometimes refer to this data format as Binary Coded Decimal (“BCD”) or unsigned packed. Example: Amount, Authorised (Numeric) is defined as “n 12” with a length of six bytes. A value of 12345 is stored in Amount, Authorised (Numeric) as Hex '00 00 00 01 23 45'. var. Variable data elements are variable length and may contain any bit combination. Additional information on the formats of specific variable data elements is available elsewhere. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 17 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 4 Terminology The EMV Contactless Specifications for Payment Systems define the processing of a transaction using a contactless card and processed on a POS System that includes Entry Point and one or more kernels, with information passed within the POS System by means of an Outcome. Each of the key terms in that sentence has a particular meaning in the specifications, as described in the following sections. 4.1 Card ..................................................................................... 17 4.2 Transaction .......................................................................... 18 4.3 POS System ......................................................................... 19 4.4 Entry Point ............................................................................ 20 4.5 Kernel ................................................................................... 20 4.6 Outcome............................................................................... 20 4.1 Card Within these specifications, a card is considered to be any consumer token supporting contactless payment transactions, whether in the form of a payment chip card, a key fob, a mobile phone, or another form factor. From the perspective of a contactless reader, the other form factors communicate and behave the same as a contactless card that is compliant with Level 1 Specifications for Payment Systems, EMV Contactless Interface Specification. With respect to cardholder verification, mobile devices may take advantage of the user interface on the handset to allow cardholder verification of a contactless transaction by means of a confirmation code entered on the handset. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 18 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 4.2 Transaction Within these specifications, a transaction (unless otherwise specified) is considered to be one conducted over the contactless interface with a contactless card. A transaction start is defined differently depending on how it is initiated. It can be initiated by the merchant, typically by entering the transaction amount. Alternatively, it can be initiated when a card enters the polling field and responds, indicating its presence. (Configuration of transaction initiation is described in more detail in section 5.6.2.) A transaction continues until the final transaction disposition is indicated to the cardholder. This may be immediately after the kernel processing for an offline approval or decline or after reception of the authorisation response if the transaction is sent online. If further communication with the card is required, then this is a part of the transaction. If another interface is requested, then the contactless transaction is concluded and a new (non-contactless) transaction is considered to start with whichever alternate interface is selected. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 19 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 4.3 POS System Within these specifications, a POS System is the device that communicates with contactless cards, processes contactless transactions, and may support other payment functionalities such as magnetic stripe or contact chip transactions. The physical architecture can be any of the following: • Fully integrated terminal: All elements included in a single device. • Intelligent card reader: The reader handles most of the contactless transaction processing, passing the results for completion by the terminal. • Combination of terminal and transparent card reader: The reader provides communication with the card, whilst kernels and other processes are in the terminal. The second and third architectures are representative of adding a contactless reader to an existing contact terminal that may already be deployed. The basic functions of the POS System include: • communication with contactless cards • application selection and kernel activation • displaying messages to the cardholder • displaying messages to the merchant • accepting merchant data entry of the transaction amount • cardholder verification (e.g. signature) • provision of online connections • provision of data capture for clearing and settlement EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 20 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 4.4 Entry Point Within these specifications, Entry Point is software in the POS System that is responsible for the following: • performing pre-processing • discovery and selection of a contactless application that is supported by both the card and the reader • activation of the appropriate kernel • handling of Outcomes returned by the kernel, including passing selected Outcomes to the reader Under exception conditions, Entry Point may return an Outcome to the reader as a result of its own processing. Detailed information about Entry Point is provided in Book B. 4.5 Kernel Within these specifications, a kernel is software in the POS System that processes certain contactless transactions. Entry Point selects a kernel based on the characteristics of the transaction, the applications supported by both the card and the reader, and the priority that may be assigned to each application. Detailed information about the kernels is provided in Books C-n. 4.6 Outcome An Outcome is the primary instruction from the kernel on how processing should be continued. A set of parameters with the Outcome allow the kernel to indicate choices, such as messages to be displayed and whether the kernel wishes to be restarted, for example, after an online authorisation. When a kernel provides an Outcome, control is passed back to Entry Point which handles certain parameters immediately, then either processes the Outcome or forwards it to the reader as a Final Outcome. Note: Under exception conditions, Entry Point may not be able to select a kernel and will directly provide a Final Outcome and pass control back to the reader. Detailed information about Outcomes is provided in Chapter 6. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 21 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5 POS System Architecture This chapter discusses the architecture of the POS System. The following topics are included: 5.1 POS System Descriptive Model ............................................ 21 5.2 Terminal and Reader Responsibilities................................... 23 5.3 Logical Architecture .............................................................. 24 5.4 Operating Modes .................................................................. 25 5.5 POS System Functions......................................................... 26 5.6 POS System Configuration ................................................... 31 5.7 Transaction Data .................................................................. 35 5.8 Entry Point Processing ......................................................... 38 5.9 Kernel Processing ................................................................ 41 5.1 POS System Descriptive Model To accommodate the broad range of possible architectures discussed in section 4.3 without developing detailed requirements for all the individual elements, EMVCo has based its design on the descriptive model shown in Figure 5-1Figure 5-1. Conceptually this is along the lines of an intelligent reader device as this is considered to be the most widespread architecture; however, it is not intended to be prescriptive. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 22 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. Figure 5-1: POS System Descriptive Model The right hand element represents a reader which communicates with the contactless card and processes the contactless application. It therefore includes the functionality of Entry Point and the contactless kernels. It would also normally contain the user interface of cardholder-facing display, visual status indicators (such as lights or LEDs), and beeper. The left hand element maps more closely to an EMV contact terminal and includes the merchant input and display, the online communications interface, plus any contact or mag-stripe interfaces. Functions such as signature CVM or online PIN CVM are expected to be acquired the same way as for an EMV contact terminal. Most of the EMV Contactless Specifications for Payment Systems address the reader element; this includes the Communication Protocol to a contactless card (Level 1 Specifications for Payment Systems, EMV Contactless Interface Specification), Entry Point (Book B), and the contactless kernels (Books C-n). 123 456 789 C0E Display COMMS POS System Final Outcome Activate (with Data) Terminal Data Exchange Display Reader 123 456 789 C0E Display 123 456 789 C0E 123112233 456445566 789778899 C0ECC00EE DisplayDisplay COMMS POS System Final Outcome Activate (with Data) Terminal Data Exchange Display Reader DisplayDisplay Reader EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 23 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.2 Terminal and Reader Responsibilities Within the descriptive model the reader is responsible for: • communication with contactless cards • application selection and kernel activation • running the contactless kernel applications • CVM selection • creation of a Final Outcome and parameter set • management of a “no card response” timeout • management of the contactless field Whilst the terminal is responsible for: • provision of data entry (amount) by the merchant • processing of Final Outcomes, including the handling of authorisation requests and responses • cardholder verification (unless delegated to a cardholder device, such as a mobile phone) • communication for authorisation messages and clearing records, using mag-stripe or chip-based data • transactions on other interfaces (contact and mag-stripe) • other aspects of transaction processing, including timeouts and cancellations Depending on the design, the terminal and reader are between them also responsible for: • initiation of new transactions, including card removal and the contactless field state between transactions • displaying messages to the merchant • displaying messages and status to the cardholder • provision of Unpredictable Numbers • provision of data included in online responses, including Authorisation Response Code, Issuer Authentication Data, and Issuer Scripts • indication of “unable to go online” With respect to performance, the reader will be mostly responsible for the “card in field” timing and the terminal for the transaction disposition timing. For details see section 10. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 24 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.3 Logical Architecture Figure 5-2: Logical Architecture The reader contains Entry Point and a set of kernels, as illustrated in Figure 5-2Figure 5-2. Terminal and reader requirements in Chapter 8 are based on this model but can be distributed differently between the elements denoted as the terminal and the reader. Nevertheless, for the overall architecture described here to work successfully with all merchant/acquirer acceptance environments, the functional requirements of Chapter 8 must be met. Additional Functionalities: UN, Amount, Configuration Handling, UI, Removal Procedure Other Services: Field control, UI, etc. Reader Entry Point Start Var Amount Fixed Amount IAD, Issuer Scripts Amount, Type of TX, Other TX data Other Services: Exception files, Etc. Online Authorisation Terminal Request Processing Data Exchange Final Outcome Pre-processing Protocol Activation Combination Selection S e le c t N e x t T r y A g a in A p p r o v e d D e c l in e d O n l in e R e q u e s t T r y A n o t h e r I / F R e q u e s t O n li n e P I N E n d A p p li c a t i o n Kernel Processing Outcome Processing Kernel Activation Functions in scope of EMV CL Specs Not in scope A B C D New Transaction Additional Processing ●CVM ●Online Auth ●… ... Restart EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 25 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.4 Operating Modes A terminal is installed in an acceptance environment that can handle mag-stripe data, chip data, or both. This information is provided in the Kernel Configuration Data and in conjunction with the card presented will determine the operating mode of an individual transaction: mag-stripe mode or EMV mode. Mag-stripe mode transactions are usually sent online for authorisation, whereas EMV mode transactions may complete offline in the interest of speed, and can be sent online when the situation requires it. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 26 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.5 POS System Functions This section discusses the following POS System functions: 5.5.1 Non-interference with Contact Chip Interface ........................ 26 5.5.2 No Overlapping Transactions ............................................... 27 5.5.3 Cancellation ......................................................................... 27 5.5.4 Field Management ................................................................ 28 5.5.5 Displaying Amount................................................................ 28 5.5.6 Transaction Disposition ........................................................ 28 5.5.7 Receipts ............................................................................... 29 5.5.8 Cardholder Verification ......................................................... 29 5.5.1 Non-interference with Contact Chip Interface For a POS System capable of accepting transactions over multiple interfaces, all permitted interfaces should be made available to the merchant/cardholder to perform a transaction. If the cardholder chooses the contact interface, to prevent interference between the contact chip and contactless interfaces, the POS System must power down the contactless interface prior to initiating a contact chip transaction and keep it powered down for the duration of the transaction. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 27 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.5.2 No Overlapping Transactions The POS System is responsible for ensuring that a new transaction is not started until the completion of the previous transaction. The completion of a transaction is a combination of the terminal having a transaction disposition and the physical removal of the card from the field. In some environments it may be necessary to employ a removal procedure to ensure that the card has left the field, whereas in others the physical configuration and the way the transaction completes may be sufficient. Examples: In some environments, such as a vending machine where the user has to physically collect goods from the bottom of the machine, it is unlikely that the card will be left on the reader or that the next customer will try to make a purchase before the first customer has moved away. Such a POS System could have simple logic to manage card removal and initiation of the next transaction. In other environments, such as access through a gate or turnstile, it may be important that the POS System checks that a card has been physically removed and that the next transaction is not initiated until the first customer has made sufficient progress through the gate. Note that a removal procedure for the card as defined in Level 1 Specifications for Payment Systems, EMV Contactless Interface Specification, section 9.5, could be started when the kernel indicates the Card Read Successfully status, 1 as this is the earliest point in a transaction after which cards can be removed. Kernels may require a mobile device to be re-presented after entry of a confirmation code and this may be addressed by means of a restart. Some kernels may require the POS System to check that the mobile device was actually removed from the field after the first presentment, possibly by use of the removal procedure between the Final Outcome and the restart. 5.5.3 Cancellation Once a transaction has been started, there must be a means to cancel the transaction in case the user is unable to present a contactless card within a reasonable amount of time. This may be by means of a timeout or merchants may have a cancel option. To handle these scenarios, depending on the implementation, the POS System may attempt to complete the transaction using another interface, or may terminate the transaction. 1 Status values are discussed in section 9.2. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 28 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.5.4 Field Management Whether the field is on or off between transactions will depend on the acceptance environment, and the POS System is responsible for ensuring the field condition. For environments with Autorun “No”, the field is off between transactions; with Autorun “Yes”, the field is on between transactions. This does not preclude the POS System from manipulating the field whilst ensuring the transaction is complete. (Autorun is described in more detail in section 5.6.2.) Additionally, it is generally recommended for Kernels to always request a field reset or power-off (depending on factors such as cardholder device formfactor) at the end of transaction, for example, by setting an appropriate value for the Outcome Parameter, Field Off Request. 5.5.5 Displaying Amount In acceptance environments where the Transaction Type and the exact amount are known before the start, the amount must be indicated to the cardholder, preferably by means of a terminal/reader display. In some circumstances the amount may be displayed by labels, such as posted prices on a vending machine. This is typical for EMV mode environments (with Autorun “No”) where the Transaction Type and amounts are made known to the reader as the transaction is started. Other environments may not know the Transaction Type or amount until the interaction with the card is complete. This is typical for mag-stripe mode environments (with Autorun “Yes”). 5.5.6 Transaction Disposition The POS System is responsible for indicating the transaction disposition to the cardholder. The transaction disposition may be obtained directly from the Outcome (if Approved or Declined), or it may be necessary that an online authorisation be completed first. The manner of indication may be via a message, vending of goods, granting or denying access, or other functions. An online authorisation will either result in a response with a Response Code and possible EMV TLV data, or will timeout and be considered as unable to go online. In EMV mode environments, typical EMV TLV data elements that may be present are Authorisation Response Code (Tag '8A'), Issuer Authentication Data (Tag '91'), and Issuer Script Template (Tag '71', '72'). EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 29 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.5.7 Receipts The POS System may have acceptance rules relating to receipts, specific to location, environment, and possibly payment system. In such cases, an ‘N/A’ in the Outcome parameter Receipt indicates that the kernel has no preference and that these rules should be applied as applicable. 5.5.8 Cardholder Verification Under certain circumstances when performing a contactless transaction, the POS System may be required to request Cardholder Verification to ensure that the person presenting the card is the person to whom the application in the card was issued. The kernel should be aware of the CVM capabilities of the POS System (e.g. the capability to print a Signature, or for Online PIN CVM the presence of a PIN entry device and acquirer online message capabilities). As described in section 5.9, once the kernel has finished processing the contactless transaction, an Outcome is indicated by the kernel. For some Outcomes the Outcome parameters set by the kernel may indicate a request for Cardholder Verification or indicate that Cardholder Verification has already taken place. The identified CVMs and corresponding requirements are described below: Online PIN The kernel requests that an online transaction includes a PIN. • The cardholder is prompted for PIN entry. • The PIN is encrypted and included in the online authorisation request. • If the timeout function supporting the Removal Timeout has been requested in the Outcome parameters, then it should be deferred until the completion of PIN entry. Confirmation Code Verified The kernel indicates that the consumer has positively completed a CVM on their consumer device (e.g. mobile phone). This may be as a result of a single presentment with the Confirmation Code pre-entered by the cardholder, or it may be the result of two presentments with a restart and the Confirmation Code being entered by the cardholder when prompted by the kernel. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 30 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. Obtain Signature The kernel requests that a signature be obtained from the cardholder. • If the terminal supports signature capture on a transaction receipt, then the terminal prints a receipt with a signature entry line. • If the terminal supports signature capture via screen entry, then the terminal displays the signature screen panel. • The cardholder is prompted for a signature. No CVM The kernel indicates that no cardholder verification is required for this transaction and no CVM should be requested. N/A The kernel indicates no CVM preference. The POS System may have acceptance rules relating to CVM, specific to location, environment, and possibly payment system. In such cases, an ‘N/A’ indicates that the kernel has no preference and that these rules should be applied as applicable. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 31 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.6 POS System Configuration The POS System must have configuration data that defines: • country and currency codes • how a transaction is initiated (by terminal action or automatically after a previous transaction is completed) • the supported operating modes • the types of transaction supported • for each combination of transaction type, application, and kernel, both Kernel Configuration Data and Entry Point Configuration Data Details about the various types of configuration data are provided in the following sections. 5.6.1 POS System Country and Currency Codes The POS System must be configured with a Terminal Country Code (Tag '9F1A') and with one or more Transaction Currency Codes (Tag '5F2A'), depending on whether multiple currencies are supported. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 32 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.6.2 POS System Configuration for Starting a Transaction The POS System must be configured such that a contactless transaction is either initiated by terminal action or starts automatically after the previous transaction has completed. The configuration parameter is Autorun [No, Yes]. Support for the Autorun parameter is optional. If the Autorun parameter is not supported, then the POS System must function as if the value of Autorun is “No”. If the value of Autorun is “No”, then the transaction start is initiated by the merchant, typically by entering the amount. If the value of Autorun is “Yes”, then the transaction start is when a card enters the polling field and responds, indicating its presence. In general “No” is for environments supporting EMV mode transactions, where the terminal needs to know the amount before starting a transaction, the field is off between transactions, and the reader is dependent on and under control of the terminal. “Yes” is generally for environments supporting mag-stripe mode transactions, where the field is on between transactions, and the reader does not depend on the terminal and initiates contactless transactions independently. Depending on the acceptance environment, the Autorun parameter is not constrained as above. For example, environments supporting EMV mode transactions with a fixed amount and field on between transactions could use Autorun “Yes” and environments supporting mag-stripe mode transactions with manual start and field off between transactions could use Autorun “No”. 5.6.3 POS System Configuration for Acceptance Environment The operating modes supported by a POS System will depend on the acceptance environment and acceptance rules. Kernels need to know this in order to request the necessary data elements and execute the applicable processing flow. Therefore configuration data is provided to the kernel by the POS System indicating the operating modes that it supports: • EMV mode • Mag-stripe mode • Both EMV mode and mag-stripe mode This terminology is generic for the purposes of this specification. The actual configuration parameters will vary per Combination {AID – Kernel ID} and details of the parameters for each kernel can be found in the corresponding Book C. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 33 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.6.4 POS System Configuration for Type of Transaction The POS System needs to know the types of transaction it supports, from the following list: • Purchase • Purchase with cashback • Cash Advance (cash withdrawal) • Refund In order for a kernel to function correctly, it needs to know about the environment in which it is installed and what can be expected of Entry Point and the terminal. The functionality can differ for the type of transaction and between AIDs supported by a given kernel. In order for Entry Point processing to match kernel expectations, the reader must be configurable with respect to the kernels and AIDs it supports. For each type of transaction supported, this list of Combinations {AID – Kernel ID} can be represented by a table, as indicated by the example in Table 5-1Table 5-1. Table 5-1: Example Combination Table per Transaction Type AID1 AID2 … AIDn-1 AIDn Kernel 2  Kernel 3   Kernel 4  Kernel 5   Kernel 6  Kernel 7   Kernel 8    EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 34 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.6.5 Kernel and Entry Point Configuration Data For each supported combination {AID – Kernel ID }, the reader has: 1. Kernel Configuration Data – For each supported type of transaction, A set of static data for kernel configuration. The value of this data is persistent from one transaction to the next and represents configuration information such as the mode (EMV / mag-stripe), CVM support, online/offline capabilities, and the RID-specific CA public key dataset. Updates of the values are exceptional and always occur outside of transaction processing. Details of the data that must be configured for each kernel can be found in the corresponding Book C. Note: Tag values can have different meanings for different kernels. The appropriate data set will be available to the kernel selected by Entry Point. 2. Entry Point Configuration Data – For each supported type of transaction, A set of static data for Entry Point processing. Again, the value of this data is persistent and represents transactional configuration information, such as contactless limits and CVM limits. Exceptional updates happen outside of transaction processing. Table 5-2Table 5-2 defines the available data set for each Combination. All configured data sets will be available for Entry Point processing. All elements defined in Table 5-2Table 5-2 are optional and may be omitted from a specific instance of a combination. Table 5-2: Entry Point Configuration Data per Combination Status Check Support flag, if present Zero Amount Allowed flag, if present Zero Amount for Offline Allowed flag, if present Reader Contactless Transaction Limit, if present Reader Contactless Floor Limit, if present Terminal Floor Limit (Tag '9F1B'), if present Reader CVM Required Limit, if present Terminal Transaction Qualifiers, if present Extended Selection Support flag, if present EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 35 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.7 Transaction Data Entry Point uses the data sets described in section 5.6.5 during Pre-Processing to compute the Entry Point Pre-Processing Indicators for each combination, as defined in Table 5-3Table 5-3. The indicators are made available to the kernel selected by Entry Point. Entry Point temporarily stores the computed indicators to support selection of another combination for the same transaction or reactivation of a kernel after an Online Request Outcome or a Request online PIN Outcome. In addition to the configuration data discussed above, each kernel will need data that is specific to the transaction. Typical transaction-specific data elements are listed in Table 5-5Table 5-5. Table 5-3: Entry Point Pre-Processing Indicators Status Check Requested Contactless Application Not Allowed Zero Amount Reader CVM Required Limit Exceeded Reader Contactless Floor Limit Exceeded Copy of TTQ (if present as part of configuration data); for definition, see Table 5-4Table 5-4 EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 36 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. Table 5-4: Terminal Transaction Qualifiers Byte Bit Definition 1 8 1b – Mag-stripe mode supported 0b – Mag-stripe mode not supported 7 RFU (0b) 6 1b – EMV mode supported 0b – EMV mode not supported 5 1b – EMV contact chip supported 0b – EMV contact chip not supported 4 1b – Offline-only reader 0b – Online capable reader 3 1b – Online PIN supported 0b – Online PIN not supported 2 1b – Signature supported 0b – Signature not supported 1 1b – Offline Data Authentication for Online Authorizations supported 0b – Offline Data Authentication for Online Authorizations not supported 2 8 1b – Online cryptogram required 0b – Online cryptogram not required 7 1b – CVM required 0b – CVM not required 6 1b – (Contact Chip) Offline PIN supported 0b – (Contact Chip) Offline PIN not supported 5-1 Each bit RFU 3 8 1b – Issuer Update Processing supported 0b – Issuer Update Processing not supported 7 1b – Consumer Device CVM supported 0b – Consumer Device CVM not supported 6-1 Each bit RFU 4 8-1 Each bit RFU EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 37 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. Table 5-5: Example Transaction-specific Data Elements Data Element Tag Notes Transaction Type '9C' See Table 5-6Table 5-6 regarding the values of these data elements. Amount, Authorised (Numeric) '9F02' Amount, Other (Numeric) '9F03' Unpredictable Number '9F37' Transaction Currency Code '5F2A' Transaction-specific only if multiple currencies are supported. The type of transaction, amount, and cashback amount are known to the terminal and are mapped as described in Table 5-6Table 5-6. Table 5-6: Type of Transaction Type of Transaction Transaction Type (Tag '9C') Amount, Authorised (Numeric) (Tag '9F02') Amount, Other (Numeric) (Tag '9F03') Purchase '00' Purchase amount Zero Purchase with cashback '00' or '09' Sum of purchase and cashback amount Cashback amount Cash Advance '01' Withdrawal amount Zero Refund '20' Amount to be refunded Zero Details of the data that must be available for each kernel can be found in the corresponding Book C. For example, a kernel that supports Online Response may also require online response data such as Issuer Authentication Data and Issuer Scripts. Note: Tag values can have different meanings for different kernels. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 38 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. 5.8 Entry Point Processing Entry Point is responsible for processing the configuration data, the discovery and selection of a mutually supported contactless application, activation of the appropriate kernel, and handling of the Outcome when the kernel finishes (including processing selected Outcome parameters and passing the Outcome to the reader). Under exception conditions, Entry Point may return an Outcome to the reader as a result of its own processing. The mechanism to select an application is designed around the presence of a Proximity Payment System Environment (PPSE) in the card. This allows Entry Point to obtain all the available brands and applications with a single command and to make an immediate choice based on priority and kernel availability. The use of additional proprietary selection methods is not precluded but is outside of the scope of this specification. Users of such methods should be aware of the potential negative impact on performance introduced by any increase in the number of commands. The method also must deal with the complexity of managing priorities amongst all available brands and applications. 5.8.1 Starting Conditions For environments in which the field is normally off, Entry Point will not be started for a new transaction before the POS system knows that the card has been removed from the field (e.g. by using a removal procedure) and the normal start conditions (such as amount entry) have been fulfilled. This is typically the situation for EMV mode environments. For environments in which the field is normally on, Entry Point will be started for a new transaction before the POS system knows that the card has been removed from the field (e.g. by using a removal procedure). This is typically the situation for mag-stripe mode environments. It does not however preclude that merchant interaction might be required to turn on the field, perhaps for power saving in battery powered devices. Entry Point may start at any of several start locations, depending on the environment and, if it is being restarted within a transaction, depending on the characteristics of the first Final Outcome. Start A Start A is normally used for a new transaction in an EMV mode acceptance environment where the field is off between transactions and the amount is variable and determined (e.g. by merchant entry) before the transaction can start. When starting at Start A, configuration data supplied by the POS System is processed for each supported Combination to produce the Entry Point Pre-Processing Indicators. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 39 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. Start B Start B is normally used for a new transaction in a mag-stripe mode acceptance environment where the field is on between transactions and the amount is fixed or not needed for the contactless processing. When starting at Start B, there is no Pre-Processing and the Entry Point Pre-Processing Indicators have fixed values. Environments with a fixed amount (e.g. a vending machine with identically priced goods) that may normally have the field off between transactions do not need Pre-Processing and can use Start B. Start B can be also used when Entry Point is restarted within a transaction, either after an online request or if a card is to be re-presented (e.g. mobile device with confirmation code). Start C and Start D Start C is used when Entry Point is restarted within a transaction in order to attempt a different Combination {AID – Kernel ID}. Start D is used when Entry Point is restarted within a transaction in order to process data provided in response to an online request, for risk management purposes. When starting at Start C or Start D, Entry Point provides the kernel with the original Entry Point Pre-Processing Indicators. 5.8.2 Application Selection and Kernel Activation The selection mechanism is designed around the use of a PPSE. For multi-brand acceptance, this allows Entry Point to obtain all the available brands and applications with a single command and to make an immediate choice based on priority and kernel availability. A PPSE response returned by a card contains one or more File Control Information (FCI) data elements forming a list of products supported by the card, the kernel they will run with, and their priority relative to one another. Note: Cards may indicate in the PPSE response via inclusion of the Terminal Categories Supported List (tag '9F3E') and/or Selection Data Object List (tag '9F3F') that additional terminal information be provided by Entry Point. This terminal information may be used by the card to adjust the list of applications used for application selection. Entry Point implementations that support the SEND POI INFORMATION (SPI) command issue the command to send the requested terminal information to the card, and the card response is the list of applications to use for application selection. EMV® Contactless Specifications for Payment Systems Book A v2.12 Page 40 / 115 © 2011-2026 EMVCo, LLC. All rights reserved. Reproduction, distribution and other use of this document is permitted only pursuant to the applicable agreement between the user and EMVCo found at www.emvco.com. EMV ® is a registered trademark or trademark of EMVCo, LLC in the United States and other countries. Entry Point compares the ADF Names and Kernel Identifiers with the transaction type specific set of Combinations of AIDs and kernels that it supports for the given transaction type. The result is a list of Combinations, prioritised according to priority value or (for equal priority matches) by their order in the FCI list. AIDs and ADF Names can be obtained from the relevant payment system. Existing cards that are already deployed do not have a Kernel Identifier in the FCI data; Entry Point reads absence of a Kernel Identifier as ‘existing application’. The type of existing application is determined from the AID. The current mapping is as follows: Kernel 2 for MasterCcard AIDs Kernel 3 for Visa AIDs Kernel 4 for American Express AIDs Kernel 5 for JCB AIDs Kernel 6 for Discover Network AIDs Kernel 7 for UnionPay AIDs Exceptions to the above may occur if Entry Point has a specific setting for the linkage between a product and a kernel. In the final selection, Entry Point picks the Combination with the highest priority, sends the SELECT AID co