| AAV |
Account Authentication Value — cryptographic proof sent during card authentication. |
| ACS |
Access Control Server — issuer system handling 3-D Secure authentication. |
| AFT |
Account Funding Transaction — when a card funds another account or wallet. |
| AML |
Anti-Money Laundering regulations. |
| API |
Application Programming Interface — rules that allow systems to communicate programmatically. |
| BIN |
Bank Identification Number — first 6–8 digits of a card number identifying the issuer. |
| BNPL |
Buy Now, Pay Later — short-term consumer financing model. |
| BSP |
Business Service Provider — company offering outsourced payment or processing services. |
| CIT |
Customer-Initiated Transaction — a payment triggered by the cardholder. |
| CNP |
Card-Not-Present — payment where the card isn't physically used (e-commerce, app, phone). |
| CP |
Card-Present — payment made in person via POS terminal. |
| CVC / CVV |
Card Verification Code/Value printed on cards to verify authenticity. |
| DCC |
Dynamic Currency Conversion — lets customers pay in their home currency at POS, often with markup. |
| DMS |
Deferred Merchant Settlement — payout made after funds clear, common in travel and ticketing. |
| EMV |
Europay-Mastercard-Visa — global chip-card standard for secure in-person transactions. |
| EPI |
European Payments Initiative — project to create a pan-European payment scheme. |
| EP2 |
EFT/POS Protocol 2 — Swiss-origin POS standard for terminal-acquirer communication. |
| FX |
Foreign Exchange — currency conversion in cross-border transactions. |
| HSM |
Hardware Security Module — secure device for encryption and key storage. |
| IC++ |
Interchange Plus Plus — transparent pricing model showing cost components. |
| IIN |
Issuer Identification Number — modern term for BIN. |
| KYC |
Know Your Customer — legal requirement to verify customer or merchant identity. |
| MCC |
Merchant Category Code — 4-digit classification defining merchant industry and risk profile. |
| MDR |
Merchant Discount Rate — total fee charged to merchants per transaction (interchange + scheme + acquirer margin). |
| MIT |
Merchant-Initiated Transaction — a payment triggered by the merchant using stored credentials. |
| MOTO |
Mail Order / Telephone Order — manual card-not-present transaction. |
| MPI |
Merchant Plug-in — software component that connects merchants to 3-D Secure systems. |
| MSF |
Merchant Service Fee — another term for the total transaction cost charged by the acquirer. |
| NCA |
National Competent Authority — regulator enforcing PSD2 compliance in each EU state. |
| NFC |
Near Field Communication — technology enabling contactless payments. |
| OTP |
One-Time Password — temporary code used in SCA or 3-D Secure authentication. |
| PAN |
Primary Account Number — long card number identifying the cardholder's account. |
| PCI DSS |
Payment Card Industry Data Security Standard — global rules for handling card data securely. |
| POS |
Point of Sale — device or environment where a card-present payment occurs. |
| PSP |
Payment Service Provider — company enabling merchants to accept electronic payments. |
| PSD2 |
Payment Services Directive 2 — EU regulation mandating security and open banking access. |
| RBA |
Risk-Based Authentication — adaptive method allowing frictionless 3-D Secure flows when risk is low. |
| SCA |
Strong Customer Authentication — two-factor requirement under PSD2. |
| SDK |
Software Development Kit for integrating payment functionality. |
| SEPA |
Single Euro Payments Area — harmonized euro transfer and direct debit network in Europe. |
| STIP |
Stand-In Processing — when card networks temporarily approve transactions for an offline issuer. |
| TC |
Transaction Certificate — cryptographic proof generated during EMV transactions. |
| TID |
Terminal ID — unique number identifying a merchant's POS device. |
| TMS |
Terminal Management System — platform used by acquirers to remotely update POS terminals. |
| TPS |
Transactions Per Second — metric for system throughput. |
| TRX |
Common shorthand for "transaction". |
| UPI |
Unified Payments Interface — real-time bank-to-bank payment system popular in India. |
| VbV / VBV |
Verified by Visa — Visa's brand for 3-D Secure authentication. |
| WPC |
Wireless Payment Controller — hardware managing contactless or mobile payment connections. |
