Payment Integration Security Checklist: 15-Item Guide Before Adding Stripe

TL;DR

Use Stripe Elements or Checkout so raw card data never touches your code. Then do the 15 items below before you take a real payment. Test mode first, secret keys server-side only, every webhook signature verified. Then keep watching for fraud once you're live.

Stripe does the heavy lifting on PCI compliance, but only if you let it. Start handling card numbers yourself, or skip webhook verification, and you've taken on liability no early-stage company wants.

Quick Checklist (5 Critical Items)

Use Stripe Elements, Checkout, or Payment LinksNever accept card numbers directly in your code

Secret key only on serversk_live_ and sk_test_ keys must never be in frontend

Store keys in environment variablesNever commit Stripe keys to your repository

Verify webhook signaturesUse Stripe's signature verification, never trust unverified webhooks

Test all flows in test mode firstUse test card numbers before going live

Never Touch Card Data 3

Use Stripe Elements, Checkout, or Payment LinksNever accept card numbers directly. Let Stripe handle sensitive data. How to set up Stripe Elements

Verify no card numbers in your codebaseSearch for patterns like 4[0-9]{15} or card_number. Should find nothing. How to scan for card data

Verify no card data in logsCheck application logs for any accidentally logged payment info. How to secure payment logs

API Keys and Secrets 4

Secret key only on serversk_live_ and sk_test_ keys must never appear in frontend code. How to secure Stripe keys

Use publishable key for frontendpk_live_ and pk_test_ keys are safe for browser. Understanding Stripe key types

Store keys in environment variablesNever commit Stripe keys to your repository. How to secure API keys

Use separate keys for test and productionDifferent environments should use different API keys. How to use Stripe test mode

Webhook Security 4

Verify webhook signaturesUse Stripe's signature verification. Never trust unverified webhooks. How to verify Stripe webhooks

Use HTTPS for webhook endpointWebhook URLs must use HTTPS, not HTTP. How to set up HTTPS

Handle all relevant eventsProcess payment_intent.succeeded, checkout.session.completed, etc. How to handle Stripe webhook events

Make webhooks idempotentProcessing the same event twice should not cause problems. How to make webhooks idempotent

Testing and Fraud Prevention 4

Test all flows in test mode firstUse test card numbers (4242 4242 4242 4242) before going live. How to use Stripe test mode

Enable Stripe Radar for fraud detectionUse Stripe's built-in fraud prevention tools. How to set up Stripe Radar

Add rate limiting to checkoutPrevent card testing attacks by limiting payment attempts. How to rate limit checkout

Monitor for unusual activitySet up alerts for high volumes, failed payments, or unusual patterns. How to monitor payment activity

Why Payment Security is Different

The stakes are higher here. A payment breach doesn't just leak data: it brings chargebacks and direct losses, can cost you the ability to process payments at all, and can land you PCI fines on top.

The good news is that Stripe does most of the hard part. With Elements or Checkout, card data never reaches your servers, which shrinks your PCI scope to almost nothing. The costly mistakes tend to sit in the parts Stripe can't do for you, like your keys and your webhooks.

Do I need to be PCI compliant?

If you use Stripe Elements, Checkout, or similar tools where card data never touches your servers, you can self-certify with PCI SAQ-A, the simplest level. Handle card data directly (you shouldn't) and you need full PCI compliance.

What if my Stripe secret key is exposed?

Roll it in the Stripe Dashboard right away. Anyone holding your secret key can create charges, issue refunds and read customer data. Then update your environment variables and go through recent activity for anything you didn't do.

How do I handle refunds securely?

Only authenticated admins or verified webhook events should trigger a refund. Never let a customer trigger one directly. Log every refund so you can audit them later.

TL;DR

Quick Checklist (5 Critical Items)

Never Touch Card Data 3

API Keys and Secrets 4

Webhook Security 4

Testing and Fraud Prevention 4

Why Payment Security is Different

Do I need to be PCI compliant?

What if my Stripe secret key is exposed?

How do I handle refunds securely?

Related Articles

Webhook Security Checklist

Cost of Payment Fraud

Payment Security Testing

Payment-Ready Security Scan

Payment Integration Security Checklist: 15-Item Guide Before Adding Stripe