Back to Services

Payment System Integration Services

We build payment integrations for Swedish businesses: Stripe, Swish, Klarna, Adyen. Card data stays with the provider, webhooks are idempotent, and refunds and reconciliation work from day one.

  • PCI DSS-Ready Integrations
  • 3D Secure 2.0
  • Mobile Payments

Payment Solutions We Integrate

Stripe

Most Popular

Cards, subscriptions and invoicing on one API

  • Credit and debit card payments
  • Stripe Checkout & Elements
  • Subscription billing
  • Invoice generation
  • Webhook handling with signature checks
  • Radar fraud prevention
  • Multi-currency support
  • Swedish Autogiro (Direct Debit)

Swish

Swedish Standard

The mobile payment Swedish customers reach for first

  • Swish e-commerce integration
  • QR code payments
  • Instant transfers
  • Refund handling
  • Payment status tracking
  • In-app Swish flows for mobile
  • TLS client certificate setup
  • Callback URL configuration

Klarna

Buy Now Pay Later

Pay later and installments, built into your checkout

  • Pay later (30 days)
  • Pay in 3 installments
  • Financing for larger purchases
  • Klarna Checkout
  • On-site messaging
  • Order management API
  • Settlement reports
  • Fraud protection

PayPal

The wallet many international customers prefer

  • PayPal Checkout
  • Express Checkout
  • Subscription payments
  • PayPal Credit
  • Venmo integration (US)
  • Dispute management
  • IPN & webhooks
  • Multi-currency

Adyen

One contract for cards, wallets and in-store POS

  • Unified payment API
  • 250+ payment methods
  • Smart routing
  • RevenueAccelerate
  • Risk management
  • Data insights
  • POS integration
  • Global acquiring

Nets (Nexi)

Card, invoice and installment payments across the Nordics

  • Easy payment gateway
  • BankAxept (Norway)
  • Dankort (Denmark)
  • Invoice & installments
  • Recurring payments
  • 3D Secure
  • Tokenization
  • Settlement reporting

Why Professional Payment Integration Matters

Security & Compliance

Done right, card data never touches your servers. We design integrations that keep you in the lightest possible PCI DSS scope, tokenize everything sensitive, and leave an audit trail you can actually show someone.

  • Guidance on PCI DSS scope and SAQ level
  • Payment data handling that satisfies GDPR
  • Tokenization instead of stored card numbers
  • Security review before and after go-live

A Checkout That Does Not Lose Sales

Extra form fields, slow redirects and failed 3D Secure challenges all cost sales at the final step. We remove steps, retry soft declines automatically, and put Swish and Klarna in front of Swedish customers instead of a bare card form.

  • Saved cards and one-click repeat purchases
  • Checkout that works with one thumb on mobile
  • Automatic retries for soft-declined payments
  • Local payment methods per market

Our Payment Integration Services

E-Commerce Integration

  • Shopping cart integration
  • Fewer steps in the checkout flow
  • Product & pricing sync
  • Swedish VAT calculation
  • Shipping integration
  • Order management
  • Digital receipts & invoicing

Subscription Billing

  • Recurring payment setup
  • Plan & pricing management
  • Proration on plan changes
  • Upgrade and downgrade flows
  • Dunning flows for failed renewals
  • Usage-based billing
  • Self-service customer portal

Security & Fraud Prevention

  • 3D Secure implementation
  • Fraud rules tuned to your traffic
  • Address verification (AVS)
  • CVV verification
  • Velocity checks on cards and accounts
  • IP geolocation blocking
  • Manual review queues for edge cases

Mobile Payments

  • Apple Pay integration
  • Google Pay integration
  • Swish optimized for mobile
  • Mobile SDK implementation
  • QR code payments
  • In-app purchase integration
  • Mobile wallet support

Multi-Currency & Markets

  • Currency conversion
  • Local payment methods per market
  • Dynamic currency conversion
  • Exchange rate management
  • Compliance per market
  • Checkout in the customer's language
  • Settlement in multiple currencies

Reporting & Analytics

  • Real-time transaction monitoring
  • Revenue dashboard
  • Churn analysis for subscriptions
  • Performance per payment method
  • Settlement reconciliation
  • Custom reports
  • Export to accounting systems

Technology Stack

Payment SDKs

  • Stripe SDK (Node.js/React)
  • Swish Merchant API
  • Klarna SDK
  • PayPal SDK

Frontend

  • Next.js/React
  • Stripe Elements
  • React Hook Form
  • Zod validation

Backend

  • Node.js/TypeScript
  • Webhook handling
  • Queue systems (Bull/BullMQ)
  • Event-driven architecture

Security

  • TLS 1.3
  • Azure Key Vault
  • Token vaulting
  • WAF (Cloudflare/Azure)

Ready to Accept Payments?

Tell us what you sell and to whom. We will recommend a provider mix for your market, flag the compliance work up front, and scope the first integration before any code is written.