What payment integration actually costs you

Every payment integration looks simple in the proposal: add a gateway, support the popular methods, done. That estimate is usually right about the checkout screen and wrong about everything downstream.

The checkout is the easy part

Connecting a payment gateway is a well-understood job. FPX, cards, GrabPay and e-wallets all have documented APIs, sandboxes and reasonable error codes. A working checkout flow can be done in days.

Reconciliation is where the time goes

Once money moves, three records have to agree: what your system thinks was ordered, what the gateway says was charged, and what actually landed in the bank.

They disagree more often than people expect — partial payments, expired FPX sessions, refunds issued after settlement, e-wallet top-ups that fail halfway. Every one of those is a branch you have to handle, and each needs a visible state in the admin console so someone can act on it.

Refunds and settlement timing affect cash flow

A refund does not move money at the same speed as a payment. If your system assumes it does, reported revenue and the bank balance will drift apart, and month-end close becomes guesswork.

What to ask before you sign

• Which payment methods are supported natively, and which need custom work?
• What happens to an order when a payment expires mid-checkout?
• Can a refund be traced back to the original transaction from the admin console?
• Is there a daily settlement report that reconciles against the bank?

If a vendor cannot answer these in specifics, the integration will land as your problem — usually a few weeks before launch.