Payment Gateway Integration Checklist: JazzCash, EasyPaisa, Stripe and More
A production checklist for integrating local and international payment gateways — reconciliation, webhook reliability, retries and the edge cases most integrations miss.
Payment gateway integration looks simple in the documentation — a checkout call, a redirect, a success callback. In production, the edge cases are where real money gets lost or double-charged: webhook delivery failures, network timeouts during the exact moment a payment succeeded, and reconciliation gaps between what the gateway says happened and what your database recorded.
Webhooks are not optional, and neither is idempotency
Never rely solely on the redirect callback to confirm a payment — a customer closing their browser mid-redirect is a common way "successful" payments never get recorded. Webhooks are the source of truth, and every webhook handler needs to be idempotent, because gateways retry webhook delivery and your system must handle receiving the same event twice without double-crediting an order.
Local gateways have different failure modes than Stripe
JazzCash and EasyPaisa integrations behave differently from Stripe or PayPal in how they report pending versus failed states — a transaction can sit in a pending state for minutes during mobile network congestion, and treating "pending" the same as "failed" causes customers to be charged twice when they retry. We build explicit handling for the pending state with a defined timeout and reconciliation job, not just success/fail binaries.
Reconciliation is the safety net every integration needs
Even a well-built integration needs a daily reconciliation job that compares your recorded transactions against the gateway's settlement report and flags discrepancies — this catches the rare cases where a webhook was missed entirely due to an infrastructure issue on either side, before it becomes a customer complaint or an accounting discrepancy.
Testing beyond the happy path
Every gateway provides sandbox environments for testing declined cards and timeouts — use them deliberately to test your error handling, not just the successful payment flow. The integrations that fail in production are almost always the ones that were only ever tested against a successful transaction.
Frequently asked questions
Why did a customer get charged twice for one order?
This is almost always a webhook idempotency failure — the gateway retried a delivery notification (which is normal and expected behaviour) and the receiving system processed it as a second, separate payment instead of recognising it as a duplicate. Proper idempotency handling keyed on the gateway's unique transaction ID prevents this entirely.
How long should a "pending" payment status be trusted before treating it as failed?
This varies by gateway and payment method, but mobile wallet payments in particular can stay pending for several minutes during network congestion. We recommend a defined timeout — often 10-15 minutes — after which a reconciliation job checks the gateway's actual settlement status rather than guessing based on elapsed time alone.
The WebSool take
We've integrated JazzCash, EasyPaisa, Stripe, PayPal and card gateways into production systems across e-commerce, POS and CRM platforms — with the webhook idempotency and reconciliation safety nets built in from the start. If a payment integration needs to be bulletproof, that's exactly our focus.
