Key takeaway
Treat payment confirmation as a server-verified event tied to an order, rather than relying only on what appears in the browser.
01
Map the order before integrating
Agree when an order is created, where its reference comes from and how the payable amount is calculated. Decide what a customer sees while a payment is pending and what happens to stock or bookings during that period. Keep the order journey understandable even if the customer closes the checkout window before a result appears.
02
Check the provider requirements
Review the gateway documentation for account activation, supported payment options, required business details and the relevant integration flow. Ask the provider about availability and commercial terms for your business. A logo on a website does not mean the merchant account has been approved or that every payment method is enabled.
03
Separate browser feedback from confirmation
The customer-facing checkout can display a result, but the application must verify the provider response using the prescribed server-side process. Keep secrets on the server and associate the verified result with the correct order. Follow the provider documentation for the chosen integration instead of treating a redirected page as proof that an order has been paid.
04
Handle repeated and delayed events
Plan for a callback to arrive late or more than once. Order updates should not create duplicate fulfilment simply because an event was retried. Make it possible to reconcile a payment with the provider record when the browser journey is interrupted. Define who reviews an unclear result and how the customer can ask for help.
05
Test the less convenient paths
Use the provider test environment for successful, failed, cancelled and pending journeys. Test refreshing the page, returning after closing checkout and retrying an unpaid order. Check that a failure does not display a paid order and that a later confirmation can be handled without losing the original order reference.
06
Prepare the business handover
Agree how staff find transactions, respond to payment questions and request or track refunds using the provider-supported process. Clarify what records the business needs for fulfilment and reconciliation. Confirm the live configuration separately from a successful test run, and keep the customer support route visible wherever a payment issue might occur.
Your next-step checklist
- Define the order reference and amount calculation
- Confirm merchant setup with the chosen provider
- Verify payment responses on the server
- Handle delayed or repeated events safely
- Test cancellation, failure and interrupted checkout
- Document the support and reconciliation workflow
Further reading
Check the official documentation for current implementation details.
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