Payment Gateway Integration

We integrate Stripe, Adyen, PayPal and Braintree, which between them cover most European businesses well. Each has its strengths: some are simpler to start with, some handle complex marketplaces and cross-border flows better, some have stronger local reach. We match the provider to your volume, your markets and your accounting.

European shoppers do not all pay by card. Depending on your markets you may need bank-transfer methods, wallets, or a local acquirer, and we integrate those so you are not turning away customers who would have paid by their preferred method.

Some sectors, including gaming and other high-risk verticals, need specialist gateways and stricter controls around payments and identity. We build those integrations with the extra care they require, and we are candid about the compliance obligations that come with them rather than waving them through.

Card entry happens inside the provider’s hosted field or iframe, and what your application receives back is a token, not a card number. That token can charge the card, refund it, or bill it again for a subscription, but it is useless to a thief. This single pattern removes the biggest category of payment breach and shrinks your compliance burden to the smallest PCI self-assessment tier that applies.

Gateways confirm what happened through webhooks, and a webhook endpoint that does not verify the signature is a way to fake a paid order. We verify every incoming webhook against the provider’s signature, handle retries idempotently so a repeated message does not double-fulfil an order, and log what arrives so a dispute can be traced.

Payments fail in ways that ordinary code does not. A customer whose connection drops after the charge but before the confirmation must not be charged twice, and must not get a free order either. We build the flow to handle those states with idempotency keys and careful reconciliation, because that grey area is where money quietly leaks.

By keeping card data in the provider’s hosted field, we keep you in the lightest applicable PCI DSS bracket. We document the integration so your self-assessment questionnaire is straightforward and defensible rather than a guessing game.

Strong customer authentication is mandatory for most European card payments, and a clumsy implementation of 3-D Secure loses sales to friction. We implement it so the challenge appears when it must and stays out of the way when exemptions apply, balancing the rules against conversion.

If an acquirer or partner wants documented assurance, our offensive security team can run a penetration test focused on the payment flow and produce a report and attestation aligned to PCI DSS. That is a separate, security-side engagement with its own quote, and the integration work does not commit you to it.

Subscription billing is deceptively hard. Cards expire, renewals fail, and a naive implementation silently loses the customer. We build recurring flows that update expiring cards, retry failed payments on a sensible schedule, and handle proration and cancellation cleanly, so a temporary decline does not become a permanent churn.

Your accounts have to match the provider’s, down to the fees and the refunds. We wire payment events into your systems so orders, payouts and chargebacks reconcile automatically, which turns month-end from a manual hunt into a report your finance team can trust.

We start by mapping how money actually moves through your business: what you sell, how you refund, whether you take payment now or capture later, and which markets and methods you need. That map, not a feature checklist, is what a correct integration is built from, and it is where we catch the requirements a generic build would miss.

The integration is built against the provider’s test environment, where we can force the situations that break naive code: declined cards, expired cards, 3-D Secure challenges, duplicate webhooks and dropped connections mid-payment. Each of those gets a defined, tested behaviour before go-live.

We move to live keys in a controlled cutover, place real low-value test transactions, and watch the first days closely, because real customers find combinations no test plan predicted. Reconciliation is checked against the provider’s dashboard so your first settlement matches your records to the cent.

You get the code, the configuration and documentation of how the flow behaves in every state, including the failure cases. There is no black box you cannot touch and no dependence on one developer who happened to understand the webhooks.

At launch you get technical documentation for your developers and a plain explanation of reconciliation and reporting for your finance team, plus the maintenance points to watch as provider APIs change over time.