Key Differences Between Issuer and Acquirer PCI Compliance in Payment Processing

PCI compliance is critical for both issuers and acquirers, but their roles, obligations, and security strategies differ significantly. Issuers focus on cardholder data security from account opening to closure, managing strict requirements. Acquirers, on the other side, are responsible for secure transaction processing, merchant compliance, and tokenization during payment acceptance. Let’s have a deeper look at the differences.

Core Responsibilities

Issuers are responsible for cardholder data security from account opening to closure. They issue cards, manage accounts, process authorizations, and protect cardholder data.

Acquirers handle transaction security and ensure merchant PCI compliance. They process payments, determine PCI validation methods for merchants, and report compliance status to payment schemes twice a year. Both issuers and acquirers must validate PCI DSS compliance annually.

Tokenization Methods

Tokenization methods differ based on whether the entity is an issuer or an acquirer. Each approach addresses unique security and compliance goals tied to their roles in the payment ecosystem.

Issuer Tokenization

Issuer tokenization uses network tokens and EMV tokens generated by card networks such as Visa and Mastercard for digital wallets and contactless payments. The primary account number is replaced with an EMVCo-compliant token. This improves authorization rates and security. Issuer tokens are linked to banks and are generated for Apple Pay, Google Pay, and Samsung Pay transactions. Issuer tokens remain valid when card expiration or card replacement occurs.

Acquirer Tokenization

Acquirer tokenization uses PCI tokens generated by acquirers, merchants, or service providers for card-on-file transactions, recurring billing, stored payments, and recurring payments. These tokens are created during transaction processing and are used to reduce PCI scope for merchants and service providers, supporting seamless payment processing.

Security Protocols

Security protocols form the technical backbone of PCI compliance, with issuers and acquirers implementing distinct methods based on their operational roles. These protocols secure transactions, protect cardholder data, and meet evolving regulatory requirements.

Issuer-Specific Protocols

Issuer-specific protocols include EMV 3-D Secure for card-not-present fraud prevention through risk-based step-up challenges. EMV 3DS 2.0 offers two-factor methods, replacing static passwords with biometrics, one-time passwords (OTPs), and risk-based checks. These protocols support in-app payments, IoT payments, and browser-based payments, enhancing transaction data for authentication decisioning.

End-to-End Encryption protects cardholder data from the payment terminal to issuer systems. The data remains encrypted during transmission, with only issuer systems able to decrypt the information, ensuring that service providers do not access cardholder data.

Acquirer-Specific Protocols

Acquirer-specific protocols use Point-to-Point Encryption (P2PE) to secure cardholder data from POS systems and processors. Payment data is encrypted at the POS system and stays encrypted until it reaches a secure processing environment for decryption. P2PE requires terminal encryption, secure algorithms, key management, and decryption environments.

Token vaults store surrogate values (tokens) mapped to primary account numbers (PANs). Token Service Providers (TSPs) manage token vaults, replacing PANs with tokens for transaction processing. Only token vaults can map tokens back to PANs, and both token vaults and those using tokens must ensure PCI compliance.

Issuer vs. Acquirer PCI Compliance: Comparison Overview

Compliance Challenges

Compliance challenges include annual PCI DSS compliance validation for card issuance, sensitive authentication data, and network authorization. Visa issuers using VisaNet must be classified as a Level 1 service provider, submit a yearly Report on Compliance (RoC) from a Qualified Security Assessor (QSA), and conduct quarterly vulnerability scans. PCI DSS 4.0 requires multi-factor authentication and client-side security for payment pages.

Acquirers must validate PCI DSS compliance and ensure merchant compliance across their portfolios. Merchant validation methods and compliance status collection must be reported for Levels 1–3 merchants, with compliance status reported semi-annually. PCI DSS 4.0 emphasizes script control, payment page monitoring, script inventory tracking, change detection, script authorization, continuous monitoring, and security alerting.

Both issuers and acquirers must comply with PCI DSS 4.0 client-side security requirements by March 31, 2025.