Payment Gateway Integration in Singapore: What a Setup Covers

What a payment gateway integration service should include

Use this as a scope list when you compare quotes. If an item is missing, ask whether it is included or whether you are expected to do it.

If you are still choosing a gateway, start with our payment gateway comparison for Singapore or the head-to-head HitPay vs Stripe.

Account ownership and verification: the part you must do

Gateways are regulated, so they verify the business and the people behind it. No integrator can or should do this on your behalf with their own details.

Stripe's Singapore verification requirements say it cross-checks your business type and structure against ACRA using your UEN, accepts ACRA BizFile as the entity document (issued within the last 12 months), and requires an account representative listed on BizFile as an owner, director, partner or similar officer. HitPay also requires identity and entity verification before you can process payments.

How the integration works: checkout, webhooks and test mode

A customer pays on the gateway's secure page or a form embedded in your site. The gateway then tells your website the result. There are two ways it does that: the customer's browser comes back to your thank-you page, and the gateway sends a server-to-server message called a webhook.

The webhook is the reliable one. If the customer closes the tab or loses signal after paying, only the webhook marks the order paid. Stripe's webhook documentation says your endpoint must verify each message's signature using a signing secret, and that Stripe retries failed deliveries in live mode for up to three days. A setup that relies only on the thank-you page will lose orders.

1. 1

   Build and test in sandbox mode

   Both Stripe and HitPay offer test environments with test cards and test PayNow flows. No real money moves.

2. 2

   Test every payment method you will offer

   Card success, card decline, 3D Secure challenge, PayNow paid, PayNow abandoned, Apple Pay and Google Pay on a phone.

3. 3

   Test the webhook separately

   Pay, then close the browser before returning. The order should still show as paid in your store or system.

4. 4

   Test refunds and partial refunds

   Refund one test order in full and one in part. Check the order status, stock and customer email update correctly.

5. 5

   Switch to live keys and run one real payment

   Pay a small real amount with your own card or PayNow, then refund it. Check it appears in the dashboard and later in the payout.

6. 6

   Remove test keys and shared logins

   Live keys stay in the website settings only. The integrator's access is reduced to what is needed for support, or removed.

Receipts, GST, refunds and payouts to your bank

Payment is not the end of the job. The money has to reach your bank and your books in a way your accountant can follow.

• Receipts: show your registered business name. If you are GST-registered, your invoices or receipts need the details IRAS requires; most store platforms handle this once tax settings are right.
• Statement descriptor: set the name customers see on their card statement to something they recognise, to reduce "I don't know this charge" disputes.
• Refunds: decide who can refund and up to what amount. Gateway dashboards let you give staff limited roles.
• Payouts: check the payout schedule and that payouts go to the business bank account. Stripe's first payout typically takes longer than later ones.
• Reconciliation: payouts arrive net of fees and refunds, in batches. Your accounting software needs to split them into sales, fees and refunds. Stripe has a Xero app for this.

For the accounting side in detail, see connecting Shopify, Stripe and Xero.

Red flags when hiring someone to set up payments

Most problems with payment integrations are not technical; they are about who controls the money.

• They ask for your Singpass, NRIC photos or bank login so they can "do the verification for you".
• They want to own the gateway account and add you as a user, not the other way round.
• Live API keys are emailed or sent over WhatsApp in plain text.
• No test-mode checks or sign-off before going live.
• A monthly fee for a plugin that the gateway provides free, without explaining what extra you get.

MAS describes the regulated payment service types, including merchant acquisition, on its types of payment services page.

Typical costs: gateway fees vs setup fees

There are two different costs, and quotes sometimes blur them.

If you only need PayNow on a simple website, read how to accept PayNow on your website first; sometimes a payment link is enough and no integration is needed.

Do it yourself or get help?

If you use Shopify Payments or a hosted payment link, setup is mostly clicking through the gateway's onboarding, and you can do it yourself. Follow the test steps above anyway.

Get help when you have a custom website or booking system, need webhooks to update orders or memberships, take PayNow and cards across several channels, or want payouts reconciled automatically in Xero. Our Online Payment Setup (S$290) connects the gateway in your own account and tests it end to end; Subscriptions & Recurring Billing (S$490) adds plans, renewals and a customer portal.