Payment Gateway Selection & Fee Comparison
We compare Stripe, PayPal, Adyen, Razorpay and others on regions, methods and fees, so you pick the right gateway for your markets.
- Gateway comparison
- Fee analysis
Enterprise Solutions & Digital Transformation
Payment Gateway Integration Services
Stripe, PayPal, Razorpay and Adyen integrations with tokenised card handling, 3-D Secure, refunds and reconciliation, so customers pay smoothly and finance can trust the ledger.
- Stripe, PayPal, Adyen
- Secure tokenisation
- Refunds & reconciliation
- Subscriptions
- Years of delivery
- 8+
- Years of delivery
- Projects shipped
- 350+
- Projects shipped
- Clients across US, UK, AU & SG
- 200+
- Clients across US, UK, AU & SG
What’s included
Secure Checkout and Payment Gateway Integration, Fully Delivered
We choose your gateway, build secure checkout, handle refunds and reconciliation, and support you after launch.
-
-
Checkout Flow & Payment UX Design
We design a fast, trusted checkout with the wallets and local payment methods your customers use, reducing abandoned carts.
- Checkout wireframes
- Payment method plan
-
Gateway API & Hosted Checkout Integration
We integrate cards, wallets, UPI, ACH and bank transfers through hosted fields or direct APIs, keeping card data off your servers.
- Payment integration
- Hosted checkout
-
Subscriptions, Recurring Billing & Invoicing
We build recurring plans, trials, proration and failed-payment retries to protect revenue on subscription products.
- Billing plans
- Dunning logic
-
Refunds, Webhooks & Payment Reconciliation
We handle refunds, chargebacks and webhook events and match payouts to orders, so finance closes books without manual checking.
- Webhook handlers
- Reconciliation report
-
PCI DSS Security & Fraud Controls
We implement tokenization, 3D Secure and fraud rules and help you prepare for PCI DSS requirements for your integration.
- Tokenization setup
- Fraud rule set
-
ERP, Accounting & Platform Integration
We sync payments with your store, ERP and accounting software, such as QuickBooks or Xero, removing double entry.
- Accounting sync
- Order status mapping
-
Live Transaction Testing & Payment Support
We test every payment scenario in sandbox and live mode, then monitor success rates and fix issues after go-live.
- Test scenarios
- Payment monitoring
Need something specific?
Why Kramate
Why Business Owners Choose Kramate for Taking Payments Online
We help your customers pay easily and help you keep their trust.
-
We Compare The Fees For You
Instead of
choosing a payment company by guesswork
With Kramate
We compare costs and countries covered, and tell you which one suits your customers.
-
Card Details Never Touch Your Servers
Instead of: carrying the risk of storing card numbers
With Kramate: We use the payment company's secure forms, and a second person checks all work.
-
Every Payment Case Tried First
Instead of: finding failed payments after launch
With Kramate: We try successes, failures and refunds in practice mode and in live mode before we finish.
-
Payouts That Match Your Orders
Instead of: checking bank deposits by hand
With Kramate: We set things up so your finance team can match each deposit to an order.
-
A Price You Can Budget For
Instead of: extra charges nobody warned you about
With Kramate: You get a detailed estimate within a day, with the price paid by milestone.
Our approach
How We Run Your Payment Gateway Integration
Customers pay smoothly, you receive funds correctly, and card data stays protected.
6 clear steps 6 deliverables you keep
-
Provider Comparison
We compare payment providers on fees, supported countries, payout times and fit for your business.
-
Pay Screen Design
We design the payment screens so buyers see clear prices, can pick how to pay and know what happens next.
-
Gateway Connection
We connect your site or app to the provider, using their hosted payment page or a custom form.
-
Card Safety Checks
We follow card safety rules and add fraud checks, so card details stay off your own servers.
-
Test Payments
We run test payments for success, decline and refund, and match them to your accounting records.
-
Live Payment Launch
We switch to live payments, make a small real transaction, and keep a close watch on early orders.
Tools & technologies
Technologies We Use for Payment Integration
Secure checkouts use established gateways, wallets and monitoring, matched to your markets.
- Stripe: Online payments for cards, wallets and subscriptions.
- PayPal: Widely trusted checkout and payment option.
- Razorpay: Payment gateway for cards, UPI and net banking.
- Adyen: Global payment platform for online and in-store sales.
- Braintree: Card and wallet payments from PayPal.
- Apple Pay: One-tap checkout for Apple device users.
- Google Pay: One-tap checkout for Android and Chrome users.
- Klarna: Buy-now-pay-later option at checkout.
- Node.js: JavaScript runtime for fast web services and APIs.
- PHP: Widely used server language for websites, portals and web apps.
- React: Component-based user interfaces for web apps.
- TypeScript: Typed JavaScript that catches mistakes before release.
- Shopify: Online store platform for products, checkout and order data.
- WooCommerce: Online store plugin that runs shops on WordPress sites.
- QuickBooks: Accounting software for invoices and bookkeeping.
- Xero: Cloud accounting for invoices, bank feeds and payments.
- Postman: Designs and tests APIs during integration.
- Sentry: Catches errors and slow requests as they happen.
- Cloudflare: Speeds up and protects sites with a global network and DNS.
Expert guide
Payment Gateway Integration Services: A Complete Guide for Businesses
Payment gateway integration services connect your website, app or back-office system to the service that accepts and routes customer payments. The work spans the checkout experience, the secure handling of card or wallet data, confirming results, handling failures and refunds, and matching every payment to your accounting records.
The technical choices have consequences beyond the checkout page. How card data flows decides how much security scope your organization carries, and a weak failure path creates unpaid orders or double charges.
This guide follows a payment from start to finish, then covers PCI considerations, subscriptions, regional context in the USA, UK, Australia and Singapore, cost factors and partner selection. It is general information, not financial or legal advice; confirm requirements with your payment provider, acquirer and counsel.
What payment gateway integration services cover: the life of a payment
A gateway is the layer that securely passes payment details from your checkout to the networks that approve them. A processor or acquirer handles the movement of funds. Many providers bundle these, so confirm which roles your chosen provider fills.
- Checkout: the customer chooses a method and enters details, ideally in fields hosted by the provider.
- Authorization: the provider asks the card network or bank whether the payment is approved.
- Customer verification: extra steps such as a bank challenge may apply.
- Confirmation: your system learns the final result, ideally by a signed webhook rather than only the browser redirect.
- Fulfillment: the order is released only after confirmation.
- Settlement and reconciliation: funds arrive and are matched to orders.
- Refunds and disputes: reversals are handled and recorded.
In practical terms, a checkout is not finished until the result is confirmed. Provider documentation such as Stripe’s developer documentation (opens in a new tab) shows this flow in one public example; other providers follow similar models.
Hosted, embedded and direct integration models
| Model | How card data is handled | Effort | Typical fit |
|---|---|---|---|
| Redirect or hosted payment page | Customer pays on the provider’s page | Lowest | Fast launch, minimal compliance scope |
| Embedded provider fields | Fields from the provider appear inside your page | Moderate | Branded checkout with reduced exposure |
| Direct API with your own form | Card data passes through your systems | Highest | Rare; heavy compliance burden |
| Platform plugin | Handled by the e-commerce platform and provider | Low | Stores on WooCommerce (opens in a new tab), Shopify (opens in a new tab) or Adobe Commerce (opens in a new tab) |
Most businesses are best served by hosted or embedded fields, because they keep raw card numbers out of your systems. Platform names are examples of public documentation only, not recommendations.
Card data, PCI DSS and security
The Payment Card Industry Data Security Standard is maintained by the PCI Security Standards Council and applies to organizations that store, process or transmit card data. The PCI SSC document library (opens in a new tab) publishes the standard and supporting guidance. How much of it affects you depends on the integration model above, and your acquirer or provider can explain your obligations.
- Keep card numbers out of your servers, logs and emails wherever possible, using tokens from the provider.
- Use TLS everywhere and restrict access to payment settings and API keys.
- Store secret keys in a vault and rotate them.
- Verify webhook signatures and test the endpoint against the OWASP API Security (opens in a new tab) risks.
- Keep an audit trail of refunds and manual adjustments, with approvals for large ones.
Failed payments, refunds and reconciliation
The unhappy paths decide whether finance trusts the system. Treat them as first-class features:
- Webhooks as source of truth: confirm payments from signed notifications, as described in the Stripe webhooks guide (opens in a new tab), and handle duplicates and out-of-order delivery.
- Idempotency: a retried request after a timeout must not charge twice.
- Declines and retries: show clear messages and let customers try another method.
- Refunds and partial refunds: link each to the original order and record who approved it.
- Reconciliation: match provider payout reports to orders and accounting entries every day, flagging differences.
Subscriptions, wallets and local payment methods
Recurring billing adds cases a one-off checkout lacks: saved payment methods, renewal failures, plan changes, proration, trials and cancellations. Design the retry and customer-notification rules with your finance and support teams, not only engineers.
Customers also expect their local methods, such as digital wallets, bank transfers and regional schemes. Offer the ones your customers use, and check that your provider supports them in the countries you serve.
Preparing finance, support and operations teams
A new payment flow changes daily work outside engineering. Finance needs reconciliation reports and clear refund rules. Support needs to see payment status and know when to escalate. Operations needs to know when an order is safe to ship. Train these teams on practical test payments in the sandbox before go-live, and agree who responds when payments fail at an odd hour.
Regional considerations: USA, UK, Australia and Singapore
Payment rules differ by country and by how you take payment. The points below are a starting map; confirm specifics with your provider and counsel.
- USA: card network rules and state-level requirements apply, and consumer protection rules govern refunds and disclosures.
- UK: the Payment Services Regulations 2017 and Financial Conduct Authority oversight; the EU’s PSD2 directive (opens in a new tab) introduced strong customer authentication for Europe, and the UK has comparable requirements.
- Australia: card scheme rules and the Privacy Act 1988 for any personal data you keep.
- Singapore: the Payment Services Act 2019, overseen by the Monetary Authority of Singapore, affects some payment businesses.
Also check currency support, tax display rules and local method coverage for each market, and agree support hours for payment incidents.
Cost factors and how to plan a budget
Payment gateway integration services involve two kinds of cost: building the integration and running payments. Build effort depends on the integration model, the number of payment methods and countries, subscription logic, refund and dispute handling, accounting integration and testing. Running costs include the provider’s transaction fees and any monthly fees, which you should compare in writing across providers.
Fixed-price work suits a single checkout flow, a dedicated team suits a platform with many markets, and hourly work suits fixes and audits. Reserve budget for testing with real-world edge cases and for the reconciliation reports finance will need.
How Kramate delivers payment integrations
For payment gateway integration services, a dedicated project manager leads each engagement, daily updates arrive on Slack or Teams, and every two-week round ends with a demo so you can try test payments early. Kramate works with least-privilege access, encrypted devices, peer code review and regular security testing, signs an NDA before detailed discussions and transfers all intellectual property to you. See our approach. Related services include e-commerce development, third-party API integration and ERP implementation.
Frequently asked questions
How do you integrate a payment gateway?
Choose a provider and integration model, build the checkout with provider-hosted fields, confirm results through signed webhooks, handle failures and refunds, then reconcile payouts against orders. Test thoroughly in the provider sandbox first, including declines, refunds and repeated notifications.
What is the difference between a payment gateway and a payment processor?
A gateway securely transmits payment details from your checkout to the payment networks. A processor or acquirer moves the funds. Many providers combine both, so check which roles each one covers.
How does PCI DSS affect payment integration?
Your integration model sets how much of the standard applies. Hosted or embedded provider fields keep card data away from your servers and reduce scope. Your provider or acquirer can advise on your obligations.
Hosted checkout or custom payment form?
Hosted pages launch fastest and carry the least compliance burden. Embedded fields keep your branding with modest extra effort. A fully custom form that touches card data is rarely worth the added responsibility.
How should payment webhooks be handled?
Verify the signature, acknowledge quickly, process asynchronously, and tolerate duplicates and out-of-order events. Treat the webhook, not the browser redirect, as the record that a payment succeeded, and log every event received.
How do you reconcile payments with accounting?
Match provider payout and fee reports to orders and ledger entries every day, record refunds and disputes against the original sale, and investigate differences promptly. Automating the match saves finance considerable manual work.
Sources and further reading
- Stripe Documentation (opens in a new tab)Stripe
- PCI Security Standards Council Document Library (opens in a new tab)PCI SSC
- OWASP API Security Project (opens in a new tab)OWASP
- Stripe Webhooks (opens in a new tab)Stripe
- WooCommerce Documentation (opens in a new tab)WooCommerce
- Shopify Developer Documentation (opens in a new tab)Shopify
- Adobe Commerce Developer Documentation (opens in a new tab)Adobe
- Payment services (PSD 2) - Directive (EU) 2015/2366 (opens in a new tab)European Commission
FAQ
Frequently asked questions
Cost depends on the number of gateways, payment methods, currencies, subscription or refund needs and security review. Custom checkout design and back-office reconciliation add work. Fees charged by providers are separate. We give a no-obligation estimate within 24 hours.
We choose providers, design the checkout flow, integrate in a sandbox, test failures and refunds, then go live. Timing depends on provider account approval, which can take time, plus the number of methods and markets. Start the merchant application early.
Checkout code, webhook handlers and setup notes become yours. Kramate signs an NDA before detailed discussions, and the deliverables transfer to you. Card data goes straight to the gateway, so it never touches your servers. Merchant accounts and API keys stay in your name and secure configuration.
Yes. We integrate Stripe, PayPal, Razorpay, Adyen and others into existing websites, apps and e-commerce platforms. We match your checkout style and order system, and handle order status updates through webhooks, without rebuilding your store.
Compare supported countries and currencies, payment methods, fee structure, payout timing, fraud tools and integration quality. Your customers' preferred methods matter most. We help shortlist providers against these needs without favouring any single one. We also explain the trade-offs so you can decide with full information.
We use hosted fields or redirects so card details bypass your servers, which reduces your PCI scope. We add HTTPS, webhook signature checks and careful key storage. Your compliance level still depends on your overall setup, which we help you understand.
We run test cards in the provider sandbox for success, decline, 3-D Secure, refund, partial refund and timeout cases. We also test webhooks arriving late or twice. A small live transaction check follows before full launch.
Taking new projects
Let’s talk about your Payment Gateway Integration Services needs
Tell us about your project and get a free consultation and estimate within 24 hours.
- We reply within 4 business hours A real consultant reads your brief — no bot, no queue.
- 30-minute discovery call We dig into goals, constraints and budget. NDA signed on request.
- Proposal in 24 hours Scope, timeline, team and price — clear enough to decide on.
NDA on request You own the IP No obligation Free estimate