What do payment gateway integration services include?
Payment gateway integration services cover everything between the moment a shopper clicks "Pay" and the moment the money reconciles in your books. That includes the checkout interface, the gateway API connection, fraud rules, webhooks, refunds and the data your finance team needs.
Our payment gateway integration services work on any major platform. Plugging in a payment app is easy. Making payments reliable, fast and fully reconciled across every edge case is the real work. Custom Ecommerce has spent 15+ years in commerce engineering, and we treat payments as the most business-critical integration on any store.
Typical scope
- Gateway selection and merchant account setup guidance.
- Hosted fields, payment elements or drop-in UI for card capture.
- Digital wallets: Apple Pay, Google Pay, PayPal and Shop Pay.
- Buy now, pay later options such as Klarna, Affirm and Afterpay.
- ACH, bank transfer and net terms for B2B buyers.
- Webhooks for payment, refund, dispute and payout events.
- Reconciliation exports and ERP posting of settlements and fees.
Which payment gateways do you integrate?
We integrate the major US and international gateways on Shopify Plus, Adobe Commerce, BigCommerce, WooCommerce and custom headless stores. The best gateway depends on your markets, average order value, B2B needs and existing banking relationships.
| Gateway | Strong fit for | Notable capabilities |
|---|---|---|
| Stripe | DTC, subscriptions, marketplaces, headless builds | Payment Element, Billing, Connect, Radar fraud tools, strong APIs |
| PayPal / Braintree | Broad consumer reach, wallet-heavy audiences | PayPal, Venmo, Pay Later, vaulting for repeat buyers |
| Authorize.net | Established US merchants and B2B sellers | Customer profiles, eCheck, Accept.js tokenization |
| Adyen | Enterprise and multi-region retailers | Global local payment methods, unified commerce, platform payouts |
| Klarna, Affirm, Afterpay | Higher-ticket consumer purchases | Pay-in-installment and financing options at checkout |
Stripe integration
Stripe is our most common choice for custom and headless checkouts. We implement the Payment Element, Payment Intents with 3-D Secure, saved payment methods, Stripe Billing for recurring revenue and Radar rules tuned to your fraud patterns.
PayPal and Authorize.net integration
PayPal adds wallet reach and Pay Later financing, while Authorize.net remains popular with US merchants and B2B sellers that rely on stored customer profiles and eCheck. We often run them alongside a primary card processor.
How we help you choose a gateway
Gateway choice is a business decision as much as a technical one. Before recommending a provider, we look at where your customers are, which payment methods they already use, your average order value, your refund and dispute history, and whether you sell subscriptions, B2B accounts or through multiple vendors.
We also check platform fit. Shopify Plus limits which gateways can run inside native checkout, Adobe Commerce and WooCommerce rely on extensions of varying quality, and headless builds can use almost any gateway API. Getting this right early avoids rebuilding checkout a year later.
How we keep payments secure and PCI-friendly
The safest card data is data your servers never see. We use gateway-hosted fields and tokenization so raw card numbers go directly to the processor, which significantly reduces your PCI DSS scope.
- Tokenization and vaulting for saved cards and repeat purchases, without storing card data on your platform.
- Strong Customer Authentication through 3-D Secure, applied when the issuer or regulation requires it rather than on every order.
- Fraud screening with velocity checks, AVS and CVV rules, device signals and manual review queues for risky orders.
- Signed webhooks and idempotency keys so duplicate events never create duplicate charges or refunds.
Our security processes are ISO 27001 aligned, and infrastructure follows AWS Well-Architected practices. We help you meet your compliance obligations, but your acquiring bank and QSA remain the authority on PCI attestation.
Payments for subscriptions, marketplaces and B2B
Advanced business models need payment logic that a standard checkout plugin cannot handle. We design the flows around how you actually bill.
Subscriptions and recurring billing
Recurring revenue depends on clean renewals, smart retries for failed cards and easy self-service for subscribers. Our subscription ecommerce platform development work covers dunning, card updater services and prorated plan changes. On our subscription ecommerce case study, a specialty beverage brand expanded ARR by $1.2M and reached 88% subscriber retention.
Marketplaces and split payments
When multiple sellers share one checkout, funds must be split, held and paid out correctly. We implement Stripe Connect, PayPal for Marketplaces and Adyen for Platforms as part of multi vendor marketplace development projects.
B2B payments
Trade buyers expect purchase orders, net terms, ACH and saved cards on account. We combine card gateways with invoicing and credit checks pulled from your ERP so B2B checkout matches how your sales team already sells.
Our payment gateway integration process
We follow a six-phase delivery process with fixed-price milestones. Payment-only projects are scoped tightly, while full checkout rebuilds follow our typical 8 to 16 week timeline.
- Discovery: review markets, payment mix, fees, decline rates and fraud history.
- Checkout UX: design payment method ordering, wallet buttons, error messages and mobile layouts.
- Architecture: plan gateway APIs, webhooks, tokens and how settlements post to your ERP.
- Development: build and configure gateways, fraud rules and refund flows.
- Testing: run sandbox scenarios for declines, 3-D Secure challenges, partial refunds, disputes and currency edge cases.
- Launch: staged traffic rollout with live monitoring of authorization rates and errors.
How much do payment gateway integration services cost?
Payment gateway integration services are scoped after a free strategy call, because cost depends on how many gateways, payment methods and business models are involved. Smaller engagements start around $15,000, and payments are often delivered as part of a larger store build in the $25,000 to $60,000 range.
Key cost drivers include the number of gateways and currencies, subscription or marketplace logic, B2B terms, ERP reconciliation and whether checkout runs headless. Gateway processing fees are set by the provider, not by us. For broader budgeting, read how much does an ecommerce website cost or try the ecommerce website cost calculator.
Checkout improvements often pay for themselves. Small gains in authorization rate, fewer false fraud declines and faster wallet payments on mobile compound across every order your store processes.
Why choose our payment integration team
We have delivered 350+ ecommerce projects across 24+ verticals and hold Shopify Plus Certified Partner, Adobe Commerce Solution Partner and BigCommerce Elite Partner status. That platform depth matters, because each platform handles checkout extensibility differently.
Our team is based in Houston, Texas and supports brands across the US and internationally. After launch, 24/7 monitoring and a 15-minute critical response SLA protect your revenue if a gateway or webhook misbehaves. You own 100% of the code we write.
Get a free payment gateway integration estimate
Whether you need a new gateway, BNPL options, subscription billing or a fully custom checkout, our payment gateway integration services are built to keep revenue flowing and finance happy.
Book a free 30-minute strategy call and we will review your current checkout, recommend the right gateway mix and send a free project estimate. We reply to every enquiry within 24 hours.
