Payments that just work, in the markets that matter
Payment gateway integration for e-commerce and subscription businesses, tested across every payment path before launch.
Where this usually breaks down
A failed payment integration costs revenue silently. Unlike a broken contact form, nobody files a support ticket when checkout fails - they just leave, and try a competitor instead. The businesses most exposed to this are the ones that tested the happy path thoroughly and never tried the failure cases: an expired card, a currency the gateway doesn't support cleanly, a webhook that arrives out of order.
Subscription businesses face a second version of the same problem after launch - a card that fails on a renewal, not the initial purchase, can quietly churn a customer who never intended to cancel, if the recovery flow isn't built to catch it.
What this service actually solves
Payment gateway integration is the work of connecting a checkout or billing flow to a payment provider correctly - handling the currencies and markets that are actually relevant, structuring recurring billing so renewals behave predictably, and building recovery flows for the failed-payment cases that will happen regardless of how well the happy path works. It also means taking PCI compliance seriously at the architecture level, not bolting it on as an afterthought.
Payment gateway integration is connecting a checkout or billing system to a payment provider's API so transactions, currencies, and recurring charges process correctly and failures are recovered rather than silently lost.
How we run it
We test every payment path before launch, not just the one that processes cleanly - expired cards, declined transactions, unsupported currencies, and webhook race conditions all get exercised deliberately. For subscription flows, we build failed-payment recovery in from the start rather than adding it after churn shows up in the numbers, since a card decline on renewal is a predictable event, not an edge case.
Capabilities & deliverables
Gateway Selection & Setup
- Provider evaluation against your markets and volume
- Checkout flow implementation and testing
Multi-Currency & Multi-Market Configuration
- Currency and locale-specific checkout logic
- Local payment method support where relevant
Subscription & Recurring Billing
- Recurring charge scheduling and proration logic
- Plan changes, upgrades, and cancellations handled correctly
PCI Compliance Considerations
- Architecture that avoids unnecessary handling of raw card data
- Compliance-aware integration patterns per provider requirements
Failed Payment Recovery
- Automated retry logic for declined renewals
- Dunning communication sequencing
What's in scope, area by area
| Area | What we deliver |
|---|---|
| Checkout Integration | A tested, working payment flow connected to the selected gateway |
| Recurring Billing | Subscription logic covering renewals, upgrades, downgrades, and cancellations |
| Recovery Flow | Automated retry and communication sequence for failed renewal payments |
| Compliance Review | Confirmation the integration pattern meets the relevant PCI requirements for your setup |
How an engagement runs
Gateway & Market Review
We confirm which gateway actually fits your markets, currencies, and volume before building anything.
Checkout Integration
The checkout flow is connected to the gateway's API, covering the currencies and payment methods relevant to your customers.
Recurring Billing Setup
For subscription businesses, we configure renewal scheduling, proration, and plan-change logic.
Failed Payment Testing
We deliberately test declines, expired cards, and edge cases most launches skip, before they happen to a real customer.
Recovery Flow Build
Retry logic and dunning communication are set up for renewal failures, since some percentage of them are inevitable regardless of setup quality.
Compliance Check & Launch
We confirm the integration pattern avoids unnecessary exposure to raw card data before going live.
How this compares
| Tested Payment Integration | Happy-Path-Only Setup |
|---|---|
| Failed and declined payments are caught and recovered | A failed payment is just a lost customer |
| Renewal failures trigger automated retry and outreach | A declined renewal silently churns the subscriber |
| Multi-currency edge cases are handled deliberately | International customers hit checkout errors nobody tested for |
Most payment integrations work fine in a demo. The difference shows up months later, in the renewal failures and edge-case transactions nobody tested for at launch.
What this changes for the business
- Checkout completes correctly across the currencies and markets that matter to the business
- Declined renewal payments trigger a recovery attempt instead of a silent cancellation
- Compliance exposure is reduced by architecture, not left to be discovered during an audit
Who needs this
Subscription businesses seeing unexplained churn
If cancellations are happening without an explicit cancel action, failed renewal payments are a common, checkable cause.
E-commerce businesses expanding into new markets
A checkout that works domestically often breaks quietly on currency or local payment method assumptions abroad.
Related work
We're still building out published proof for this specific service — ask us directly and we'll walk through relevant examples.
Common questions
Stripe, PayPal, and most major providers with a documented API. Selection depends on your markets, volume, and existing platform - we'll recommend based on your specific situation rather than defaulting to one provider.
No legitimate integration can guarantee a specific conversion outcome, since checkout completion also depends on pricing, trust signals, and factors outside the payment flow itself. What a properly tested integration does guarantee is that the payment step itself isn't the reason a legitimate transaction fails.
We build using integration patterns that minimise your exposure to raw card data - typically hosted fields or tokenisation provided by the gateway - which reduces your compliance scope. Full compliance certification is a separate process that depends on your broader infrastructure, not just the checkout integration.
A properly built recovery flow retries the charge on a schedule and triggers customer communication (dunning) asking them to update their payment method, rather than cancelling the subscription immediately on the first failure.
A standard checkout integration for a single market and currency typically takes two to three weeks including testing. Multi-currency, multi-market, or subscription billing with recovery flows adds time, scoped based on how many markets and edge cases are involved.
Losing customers at checkout without knowing why?
We'll test your current payment flow across the failure cases most launches skip, before recommending a fix.
Talk to us →