Payment Gateway Testing Checklist

Create a test environment that cannot dispatch real orders

Use the gateway’s test mode with its documented test payment methods. Confirm that test orders cannot reach live fulfillment, bookkeeping, or marketing destinations. Assign a test order prefix or date range so the records can be identified later.

Test the order journey, including failures

• Verify guest checkout, signed-in checkout, mobile layout, taxes, shipping, and any supported discounts.
• Exercise an approval, decline, canceled redirect, and a delayed notification if the provider’s sandbox supports it.
• Compare the order reference, amount, currency, and gateway state after approval, refund, and a duplicate browser refresh.

Define pass and fail before launch

For each test, write the expected store state and the expected gateway state. Record what the customer sees and whether stock, email, or fulfillment events fire. A pass requires evidence from both the storefront and provider record. Keep test order IDs for diagnosing failures.