Custom Payment Gateway Integration
Payments that go through, and reconcile
We connect your site or app to the gateways your customers already pay with, then build the unglamorous parts that decide whether the money actually lands and can be accounted for.
Talk to us about your projectWhere payment projects actually go wrong
Taking a card payment is the easy part. Most gateways have that working in an afternoon, which is why so many integrations stop there. The cost arrives later: the webhook that fired twice, the customer still billed for a plan they cancelled, the refund that never reached the ledger, the month-end where the dashboard and the bank do not agree.
So we build the integration as a money system rather than a button. Every payment event is written to your own database, handlers are safe to run twice, a failure raises an alert instead of leaving a silent gap, and there is a report your accountant can actually use.
Capabilities
What the integration covers
Chosen against the markets you actually sell into. A UPI-first Indian checkout and a card-first US one are different builds, and the difference shows up in your failure rate.
Gateway integration
Stripe, Razorpay, PayPal, PayU, Cashfree, CCAvenue, Paytm, Square, Authorize.net and region-specific processors, behind one checkout flow in your product.
Local payment methods
Cards, UPI intent and collect, net banking, wallets and pay-later options, picked for the market rather than whatever the gateway defaults to.
Crypto payment rails
Coinbase Commerce, BitPay or NOWPayments where on-chain settlement matters, with the conversion and payout path agreed before launch instead of after.
Subscriptions and recurring billing
Plans, trials, coupons, proration on upgrades, and dunning that retries a failed card on a schedule rather than cancelling the customer on the first decline.
Checkout you control
A branded checkout on your own domain using the gateway's hosted card fields, so raw card data never reaches your servers and your PCI scope stays small.
Webhooks and event handling
Signed payloads, idempotent handlers, retries with exponential backoff and a dead-letter queue, so a gateway outage delays an order instead of losing it.
Refunds, disputes and chargebacks
Full and partial refunds from your own admin screens, the evidence upload flow for a chargeback, and a record of who approved each one.
Multi-currency and tax
Prices displayed in the customer's currency, GST, VAT or sales tax applied by jurisdiction, and settlement currency handled separately from what the buyer sees.
Fraud controls
The gateway's own risk engine plus rules for your profile: velocity checks, country blocks and BIN ranges, tuned so genuine customers still get through.
What you get
What you own at the end
Everything below is handed over, and none of it needs us to stay involved.
- Working checkout
- Live payments in production
- The checkout, both the success and failure paths, and the admin screens your team uses to refund a customer or resend an invoice. Source code and deployment pipeline handed over.
- Payment ledger
- Every event recorded your side
- A record of each charge, refund, retry and webhook in your own database. When the gateway dashboard and your accounts disagree, this is what tells you which one is wrong.
- Reconciliation
- A report that ties out
- Your orders matched against the gateway's settlement file, with mismatches listed rather than quietly netted off. Your finance team runs it without asking an engineer for help.
- Runbook
- Keys, webhooks and failure notes
- Which credentials live where, how to rotate them, what each webhook does, and what to check first when payments start failing at 2am. Written for whoever is on call.
How we work
From gateway choice to live money
The timings below are for a single gateway and a straightforward checkout. Subscriptions, multi-currency and marketplace-style split payments push the build closer to four to eight weeks.
Gateway selection
3–5 daysWe look at where your customers pay from, your quoted fees and settlement terms, and the methods they expect. Occasionally the answer is that your current gateway is fine.
Sandbox build
1–2 weeksCheckout, webhooks and the database side built against the gateway's test mode, with the ugly cases exercised: declined cards, duplicate callbacks, a timeout mid-payment.
Live activation
About a weekProduction keys, a small run of real transactions watched end to end, and settlement confirmed against your bank account before the flow opens to everyone.
Run and reconcile
OngoingAlerting on failed payments, gateway API version upgrades and the reconciliation job. Providers change their APIs on their own schedule, so something eventually breaks.
Is this the right service for you?
Read this before you book a call. It is faster to rule us out here than on a Zoom.
A good fit if…
- You sell online and payments are central to how the product works
- You need UPI, cards and international payments behind one checkout
- You bill on subscriptions and failed-card recovery is currently manual
- Payments mostly work, but nobody trusts the month-end numbers
Probably not, if…
- You want a Shopify or WooCommerce payment plugin configured and switched on
- You need CRM, ERP or accounting sync rather than payments — see Integrations & Custom API Development
- You still need the storefront or platform built — start with Web & SaaS Platform Development
- You want a payment aggregator licence or merchant account obtained on your behalf
Frequently Asked
Questions
Common questions about payment gateway integration.
All the major ones: Stripe, Razorpay, PayPal, PayU, Cashfree, CCAvenue, Instamojo, Paytm, Square, Authorize.net, and region-specific processors. We also integrate crypto payment rails (Coinbase Commerce, BitPay, NOWPayments) when clients need on-chain settlement.
We never touch raw card data. All payment capture runs through PCI-DSS Level 1 processors (Stripe, Razorpay, etc.), using tokenized card references on our side. That keeps your PCI scope minimal and your compliance burden manageable. For merchants who do need to store card data, we design around the requirements — but that's rarely the best path.
Yes. Full subscription infrastructure: plans and tiers, proration on upgrades/downgrades, free trials, coupon codes, automatic retries on failed payments (dunning), grace periods, cancellation flows, and webhook-driven downstream sync to your CRM / invoicing / analytics stack.
Standard for global SaaS and marketplace projects. We implement dynamic pricing in local currency, configure tax (GST, VAT, sales tax) by jurisdiction, handle currency conversion via the gateway, and manage settlement currencies separately. For high-volume cross-border, we'll also consider crypto or ACH alternatives.
A single-gateway integration with basic checkout: 1–2 weeks. Full subscription + multi-currency + webhooks + admin dashboard + refund flows: 4–8 weeks. Marketplace-style split payments (paying multiple vendors from one transaction): add 2–4 weeks.
Yes. We wire up the gateway's built-in fraud tools (Stripe Radar, Razorpay's fraud engine), add custom rules for your risk profile (velocity checks, country blocks, BIN ranges), and integrate optional third-party tools (Sift, Signifyd) for high-risk merchants.
Have a project in mind?
Fixed price after a paid discovery — no hourly billing. A real engineer reads every enquiry, and we reply within 24 hours.