Payment integration is a transaction workflow, not just a button or a redirect. Review provider eligibility, supported currencies, account approval and the platform's integration method before development begins. Technical testing should distinguish a successful browser journey from a verified transaction outcome.
Confirm the provider and account boundary
Merchant availability can depend on country, business type and provider requirements. Use approved accounts and supported sandbox methods. Do not collect card details through an ordinary enquiry form. The provider's documentation and account permissions determine which features can be implemented.
Check event handling and order state
A returning browser can close or retry without completing the transaction. Server-side verification should use the provider's supported result or authenticated event. Duplicate notifications need safe handling so an order is not processed twice. Test declines, cancellation and delayed events as well as a successful payment.
Example: the success page opens after a declined attempt
The visible page is not sufficient evidence to mark an order paid. Review the provider's verified result and the application's state transition. Staff need a clear way to identify pending or uncertain outcomes rather than relying on a screenshot.
Project checklist
- Verify account eligibility
- Use supported test transactions
- Validate provider events
- Handle duplicate and delayed notifications
- Protect payment secrets and order history