Summary

If your API touches payment card data — even briefly — you’re in scope for PCI DSS compliance. For many API-first companies, this comes as a surprise. You might assume that because you’re not storing card numbers directly, the rules don’t apply. They do. This guide breaks down exactly what PCI DSS requires for API companies, presented as an actionable checklist you can use today. Consequences include significant fines from card brands, mandatory forensic investigations (PFI), potential loss of the ability to process card payments, and reputational damage. Breach costs for non-compliant companies are substantially higher than the cost of compliance.

PCI DSS Checklist for API Companies: Everything You Need to Know

What Is PCI DSS and Why Does It Apply to API Companies?

The Payment Card Industry Data Security Standard (PCI DSS) is a set of security requirements established by the major card brands (Visa, Mastercard, Amex, etc.) to protect cardholder data. Version 4.0, released in 2022 and now the active standard, applies to any entity that stores, processes, or transmits cardholder data — including through APIs.

If your API:

Accepts payment card numbers as input
Passes card data between services or third parties
Handles authentication tokens linked to payment accounts
Sits in the data flow between a merchant and a payment processor

…then you are almost certainly in scope.

Your compliance level (SAQ type or full QSA audit) depends on transaction volume and your specific role in the payment ecosystem.

Determining Your Scope Before Building Your Checklist

Before checking anything off a list, you need to define your Cardholder Data Environment (CDE) — the systems, people, and processes that touch cardholder data.

Steps to Define Your CDE

Map your data flows: Trace every API call that could carry card data, including headers, query parameters, request bodies, and logs.
Identify all endpoints: Document which API endpoints receive, transmit, or return cardholder data.
Inventory connected systems: Include databases, logging platforms, monitoring tools, and third-party integrations.
Classify your data: Distinguish between Primary Account Numbers (PAN), CVV codes, expiration dates, and cardholder names — each has different retention rules.

Scoping mistakes are the number-one reason API companies fail PCI assessments. Get this right first.

PCI DSS Checklist for API Companies

1. Network Security Controls (Requirement 1)

[ ] Deploy and configure firewalls around all API servers in the CDE
[ ] Restrict inbound and outbound traffic to only what is necessary
[ ] Segment your CDE from non-payment systems using network-level controls
[ ] Document all network connections and update diagrams at least annually
[ ] Deny all traffic by default; allow only explicitly approved connections

2. Secure API Configuration (Requirement 2)

[ ] Change all default credentials on API gateways, servers, and databases before deployment
[ ] Disable all unnecessary services, ports, and protocols on API servers
[ ] Maintain a configuration standard for every system component in the CDE
[ ] Apply hardening guidelines (CIS Benchmarks are a good baseline) to all API infrastructure
[ ] Review configurations at least once every 12 months

3. Protecting Cardholder Data at Rest and in Transit (Requirements 3 & 4)

This is where many API companies run into trouble. Even if you don’t “store” card data intentionally, it can end up in logs, caches, or error messages.

[ ] Never log full PANs — mask or truncate card numbers in all log outputs
[ ] Ensure CVV/CVC codes are never stored after authorization — not in databases, logs, or caches
[ ] Encrypt PANs using strong cryptography (AES-256) if storage is required
[ ] Implement TLS 1.2 or higher for all API communications — no exceptions
[ ] Disable deprecated protocols (TLS 1.0, 1.1, SSL) across all endpoints
[ ] Use certificate pinning where appropriate for mobile or partner API clients
[ ] Validate that API responses never return full PANs to unauthorized clients

4. Vulnerability Management (Requirements 5 & 6)

[ ] Deploy anti-malware solutions on all API server components
[ ] Run authenticated vulnerability scans on API infrastructure at least quarterly
[ ] Perform external penetration testing at least annually (and after significant changes)
[ ] Implement a secure software development lifecycle (SSDLC) for all API code
[ ] Conduct code reviews — manual or automated — before deploying to production
[ ] Maintain an inventory of all open-source libraries and third-party dependencies
[ ] Monitor for known vulnerabilities in dependencies (tools like Snyk or Dependabot help)
[ ] Apply security patches within defined timeframes: critical patches within one month

5. Access Control (Requirements 7, 8 & 9)

[ ] Implement role-based access control (RBAC) so API keys and credentials follow least-privilege principles
[ ] Assign unique IDs to every user and system account — no shared credentials
[ ] Enforce multi-factor authentication (MFA) for all administrative access to CDE systems
[ ] Rotate API keys and secrets on a defined schedule or immediately after suspected compromise
[ ] Store API secrets in a secrets manager (HashiCorp Vault, AWS Secrets Manager, etc.) — never in code
[ ] Implement automatic session timeouts for API management consoles
[ ] Review and revoke access for terminated employees or contractors immediately
[ ] Restrict physical access to servers hosting CDE components

6. Monitoring and Logging (Requirement 10)

[ ] Enable logging on all API gateways, servers, and databases in the CDE
[ ] Log all access to cardholder data, authentication attempts, and privilege escalations
[ ] Protect logs from modification or deletion (write-once storage or SIEM forwarding)
[ ] Retain logs for at least 12 months, with three months immediately available
[ ] Set up real-time alerts for anomalous API activity (unusual call volumes, failed auth spikes)
[ ] Synchronize system clocks using NTP to ensure log accuracy across services

7. Regular Testing (Requirement 11)

[ ] Run internal and external vulnerability scans quarterly using an Approved Scanning Vendor (ASV) for external scans
[ ] Conduct annual penetration tests specifically targeting your API attack surface (injection, broken auth, excessive data exposure)
[ ] Test API security controls after any significant infrastructure or code change
[ ] Implement intrusion detection/prevention systems (IDS/IPS) on CDE networks
[ ] Review and test your incident response plan annually

8. Security Policies and Governance (Requirement 12)

[ ] Maintain a formal information security policy reviewed at least annually
[ ] Document your API security standards and make them available to all relevant staff
[ ] Conduct annual PCI DSS risk assessments
[ ] Train all personnel on PCI DSS requirements and their specific responsibilities
[ ] Maintain contracts with third-party API providers confirming their PCI compliance
[ ] Keep a complete inventory of all hardware and software in the CDE

Special Considerations for API-Specific Risks

Tokenization and Reducing Scope

Many API companies dramatically reduce their PCI scope by using tokenization. Instead of handling raw PANs, your API receives and passes tokens that map to card data stored securely by a compliant tokenization provider (like Stripe or Braintree). If done correctly, this can push much of your infrastructure out of scope.

Third-Party API Integrations

Every third-party API you connect to that touches payment data extends your risk surface. Always:

Obtain their PCI DSS compliance attestation (AOC — Attestation of Compliance)
Define responsibility boundaries in contracts
Monitor third-party API behavior for anomalies

GraphQL and REST-Specific Risks

Modern API architectures introduce unique vulnerabilities. Watch for:

Excessive data exposure — APIs returning more fields than requested, including card data
Broken object-level authorization — users accessing other users’ payment records
Mass assignment — clients modifying fields they shouldn’t, including payment status fields

Frequently Asked Questions

Do I need PCI DSS compliance if I only pass card data through my API but don’t store it?

Yes. Transmission of cardholder data puts you in scope for PCI DSS, even if you never store it. The specific requirements you must meet depend on your SAQ type, but network security, encryption, and access controls apply regardless.

What SAQ type applies to most API companies?

It depends on your role. If your API passes card data to a payment processor without storing it, you may qualify for SAQ A-EP or SAQ D (for service providers). Many API companies that handle card data on behalf of merchants are classified as service providers, which carries stricter requirements. Consult a Qualified Security Assessor (QSA) to confirm your classification.

How do I handle PCI DSS compliance when using microservices?

Each microservice that touches cardholder data is in scope. The best approach is to isolate payment-related microservices into a dedicated, tightly controlled network segment and minimize the number of services that ever see raw card data. Use internal tokenization to pass safe identifiers between services.

How often do I need to complete a PCI DSS assessment?

Annual assessments are required, along with quarterly vulnerability scans. However, PCI DSS v4.0 emphasizes that compliance should be continuous — not a once-a-year checkbox exercise. Monitoring, patching, and access reviews happen on an ongoing basis.

What happens if my API has a card data breach?

Consequences include significant fines from card brands, mandatory forensic investigations (PFI), potential loss of the ability to process card payments, and reputational damage. Breach costs for non-compliant companies are substantially higher than the cost of compliance.

Stop Building Your Compliance Program from Scratch

Working through PCI DSS requirements manually is time-consuming, and the cost of missing something is high. Our ready-to-use PCI DSS compliance templates are built specifically for API companies and SaaS providers — giving you pre-written policies, completed risk assessment frameworks, security standards documentation, and audit-ready checklists you can customize in hours, not weeks.

Get your PCI DSS template bundle today and walk into your next assessment fully prepared. Every template is aligned to PCI DSS v4.0 and reviewed by compliance professionals who understand how modern API infrastructure actually works.

[Browse PCI DSS Templates →]