Payment gateway integrations: what you need to know

Key takeaways

• Payment gateway integration connects your website, app, or POS system to a payment processor, so you can accept and process customer payments securely.

• Choosing the right integration method, API, hosted pages, plugins, or Payment Links, comes down to your technical resources, budget, and how much control you want over the checkout experience.

• Airwallex offers no-code, low-code, and API integration options with multi-currency support, local acquiring in 35+ markets, and AI-driven fraud prevention to help you collect payments globally.

When 77% of consumers are likely to abandon their cart if their preferred payment method isn't available, getting your checkout right isn't optional. The global digital payments market is set to reach US$36.75 trillion by 2029,¹ and customers expect to pay the way they want to, whether that's through digital wallets, local bank transfers, or buy now, pay later options.

That's where payment gateway integration comes in. It's the process of connecting your website, app, or point-of-sale system to a payment processor, so you can accept payments securely and offer the methods your customers truly want.

In this guide, we'll walk through how payment gateways work, the different ways to integrate one, what to look for when choosing a provider, and how to get set up quickly.

What is payment gateway integration?

Payment gateway integration is the process of connecting your business's website, app, or point-of-sale (POS) system with a payment processor. Think of it as the bridge between your customer's bank and your business. It transfers payment information securely whilst protecting sensitive details like card numbers. For businesses, integrating with a reliable payment gateway means you can offer a range of payment methods, keep payments secure, and give customers the smooth checkout experience they expect.

How payment gateway integration works

Here's what happens behind the scenes when a customer pays:

• Customer enters payment details. At checkout, the customer types in their card number, expiry date, and CVV, or chooses a saved payment method or digital wallet.

• Gateway encrypts the data. The payment gateway scrambles the sensitive information and sends it securely to the payment processor.

• Processor routes the request. The payment processor sends the transaction to the relevant card network (Visa, Mastercard, etc.), which then passes it on to the customer's issuing bank.

• Bank approves or declines. The issuing bank checks whether the customer has enough funds and whether the payment looks legitimate. It then sends back an approval or decline.

• Gateway confirms to the customer. The payment gateway gets the response and shows a confirmation, or an error message, to the customer in real time.

• Funds settle into your account. Once approved, the funds move from the customer's bank to yours, usually within one to a few business days, depending on the provider and payment method.

Think of it like ordering at a restaurant. You tell the waiter, the gateway, what you want. They take your order to the kitchen, the processor and bank, and bring back confirmation that your meal is on its way. You don't need to know how the kitchen works. You just need to know your order went through.

Now that you know what a payment gateway does, let's look at the different ways you can set one up.

Types of payment gateway integration

Different integration methods give you different levels of customisation, ease of setup, and security. The right one depends on your technical resources, how much control you want over the checkout experience, and how quickly you need to get up and running.

API integration

API integration connects your platform straight to the gateway provider's Application Programming Interface (API), which gives you full control over the payment flow. This lets you build a fully customised checkout experience that matches your brand and user interface. It also supports more advanced features like recurring billing for subscriptions, multi-currency transactions, and tokenization for securely storing payment details. The trade-off is simple: you'll need developer resources to build and maintain the integration, and you're responsible for PCI DSS compliance.

Hosted payment pages

A hosted payment page sends customers to a secure, third-party checkout page managed by the payment gateway provider. It's a bit like handing your customer over to a trusted cashier. The provider takes care of security and PCI compliance, so you don't have to. This is a good fit if you want a fast, secure solution without handling sensitive data yourself. The downside is that customers leave your site to finish the payment, which can affect the user experience and, in some cases, conversion rates.

Plugins and extensions

Plugins and extensions give you ready-to-use payment integration for popular eCommerce platforms like Shopify, WooCommerce, Magento, and BigCommerce. If you want a hassle-free, plug-and-play option, this is often the fastest way to go. Setup is minimal, and no coding is required. Airwallex offers Payment Plugins for these platforms, so you can expand your checkout capabilities without rebuilding anything. The trade-off is that you get less customisation than you would with a full API integration.

Payment Links

Payment Links give you a simple, no-code way to accept payments without a dedicated website or checkout page. You create a secure link and share it by email, SMS, or social media. The customer clicks, pays, and that's it. This works especially well for service-based businesses, freelancers, and one-time transactions. Payment Links can also sit alongside other integration methods, so you can use them for ad-hoc payments even if you already have a full checkout flow somewhere else.

Each method comes with trade-offs. So, here's what to weigh up when you're choosing one.

Benefits of payment gateway integration

Integrating with the right payment gateway does more than process payments. It can help you reach more customers, protect your revenue, and create a checkout experience that brings people back.

Accept more payment methods and currencies

Today's customers want to pay their way. Some prefer credit cards. Others go straight for Apple Pay or Google Pay. And in many markets, local methods like iDEAL (Netherlands), Pix (Brazil), or UPI (India) are the default. Buy now, pay later options like Klarna are growing too.

When you offer the payment methods your customers already use, you cut down the friction that leads to abandoned carts. And remember, 77% of consumers will leave if their preferred option isn't available. Airwallex supports 160+ local payment methods, so you can meet customers where they are.

Cut costs with multi-currency settlement

If you're selling internationally, currency conversion fees can quietly eat into your margins. Every time a foreign currency payment gets automatically converted into your home currency, you're paying for that conversion, often at unfavourable rates.

A payment gateway that's integrated with multi-currency accounts lets you settle payments in the same currency your customers pay in. That means you're not losing money to conversion fees every time someone pays in euros or yen. You can hold multiple currencies and pay out from those balances, which helps you avoid unnecessary FX costs. Look for providers that offer like-for-like settlement so you keep more of what you earn.

Protect transactions with built-in security

A secure payment gateway includes end-to-end encryption, fraud detection, and compliance with the Payment Card Industry Data Security Standard (PCI DSS). One feature that's worth understanding is tokenization. Tokenization replaces your customer's real card number with a unique stand-in, a token, that's useless to anyone who intercepts it.

Think of it like a hotel key card that only works for your room. Even if someone copies it, they can't get into anyone else's. If your system is ever breached, the tokens are meaningless without the original card details.

When you combine that with 3D Secure authentication and AI-powered fraud detection, you can catch fraudulent transactions before they go through whilst also cutting down on false declines that cost you revenue and customer trust.

Speed up checkout and reduce drop-offs

On top of offering different payment options, a modern payment gateway can make checkout faster. Features like auto-filled customer details, saved payment methods, and mobile-friendly flows mean customers spend less time typing and more time buying. Studies show that even a one-second delay in checkout can reduce conversions by up to 7%.² For SaaS and subscription businesses, recurring billing support means customers don't have to re-enter details for every payment, which reduces churn and makes renewals feel effortless.

Once you know what you're looking for, the next step is choosing a provider that fits your business.

Key considerations when choosing a payment gateway integration

Before you pick a provider, here are the factors that matter most. The right gateway should fit into your existing tech stack without forcing your IT team to rebuild everything. It also needs to keep payments secure.

PSP vs. dedicated merchant account

There are two main ways to accept payments. The first is an all-in-one payment service provider (PSP) that bundles the gateway, processor, and merchant account together.

The second is a dedicated merchant account with a separate gateway. A PSP is like a serviced office: everything's included, and you can get started quickly. A dedicated merchant account is more like leasing your own office. You get more control, but there's more setup involved. For most growing businesses, a PSP is the fastest route to accepting payments.

Airwallex works as a PSP with the flexibility of a dedicated setup, so you get speed without giving up control.

Payment methods and currency support

Today's customers want to pay their way, whether that's through local bank transfers, digital wallets, or credit cards. Letting them choose their preferred method makes checkout smoother and helps stop them from abandoning cart.

It's worth partnering with a provider that supports a wide mix of payment options and cross-border transactions without piling on extra payment gateway fees.

Security and technical compatibility

Payment security is about earning your customers' trust. Choose a payment solution that's PCI DSS compliant and includes features like fraud detection, encryption, tokenization, and 3D Secure authentication.

Make sure the platform also complies with the General Data Protection Regulation (GDPR) and other local data protection laws.

Then look at the technical side. Is it easy to integrate? Does it offer API-first flexibility for custom setups, or simple plug-and-play options for eCommerce platforms?

Make sure it works with the tools you already use, including ERP systems, accounting software, and CRM tools. And, think about your team's bandwidth too: do they have the skills for direct integrations, or would a fully managed, hosted solution save time and resources?

Cost and revenue optimisation

When you're comparing payment solutions, look at the total cost of ownership: setup, maintenance, chargebacks, and currency conversion costs. It also helps to look for competitive FX rates, automated reconciliation, and real-time transaction data, so you can spot trends and cut unnecessary costs.

Scalability for international growth

If global expansion is part of your strategy, your payment solution should support cross-border payments without friction. Choose a provider that offers multi-currency support. Multi-currency accounts let you receive, hold, and pay in various currencies without unnecessary FX conversions.

Look for local acquiring and like-for-like settlement options to reduce fees and improve authorisation rates. Payment orchestration can help here too. It dynamically shows the right payment methods based on customer location, so a shopper in the Netherlands sees iDEAL whilst a customer in Brazil sees Pix.

Make sure the provider also offers regulatory compliance in key markets to guarantee a smooth entry into new regions.

Once you've picked the right approach, here's how to get it up and running.

How to integrate a payment gateway: A step-by-step guide

Payment integration can seem complicated, but it doesn't have to be. With the right approach, you can set up a secure, scalable payment system without the hassle. Here's how to get started:

• Choose your integration method. Start by comparing providers based on security, global reach, supported payment methods, and integration flexibility. Consider options that support multi-currency transactions and local payment methods to make the customer experience as smooth as possible. Refer to the types section above to compare API integration, hosted pages, plugins, and Payment Links.

• Set up your account. A merchant account is necessary for processing card payments. The setup process varies by provider, but it usually requires business details, financial documentation, and bank account information. If you're using a PSP like Airwallex, you may not need a separate merchant account. Our Business Accounts let you settle, hold, and transfer funds without opening additional accounts.

• Get your API keys or credentials. Once the provider approves your account, you'll get API keys or integration credentials that connect your system to the payment gateway. Treat these like banking passwords and store them securely.

• Connect the gateway to your platform. Choose the integration method that fits your needs. If you want complete control and customisation, go with API integration. If you'd rather keep it simple, hosted payment pages handle security and compliance for you. Need a quick, no-code option? Use plugins or extensions for platforms like Shopify and WooCommerce. And if development resources are tight, modern payment providers also offer low-code and no-code options to help you get up and running fast.

• Test in sandbox and go live. Before you start accepting real payments, thorough testing is essential. Most providers offer a sandbox or test mode for this. Here's what to check:

  • Simulate successful and failed payments to see how your system handles each scenario

  • Test each payment method you plan to offer (cards, digital wallets, local methods)

  • Verify refund and chargeback flows work correctly

  • Check error handling and messaging, customers should see clear, helpful messages if something goes wrong

  • Confirm security settings like 3D Secure and fraud rules are active

  • Once everything is running smoothly, your payment gateway is ready to go live.

With your gateway live, the next step is making sure it keeps performing as you scale.

Collect payments globally with Airwallex

With Airwallex, you can collect payments in multiple currencies, boost acceptance rates, and cut costly FX fees, all from a single platform built for global eCommerce. Whether you're an eCommerce brand, a subscription service, or a fast-growing marketplace, we offer no-code, low-code, and fully customisable API integration options to fit your setup. Our local acquiring network spans 35+ markets, and AI-driven fraud prevention helps make sure every transaction goes through securely.

Frequently asked questions

What is payment gateway integration?

Payment gateway integration is the process of connecting your website, app, or point-of-sale system to a payment processor, so you can accept customer payments. Think of the gateway as a bridge between your customer's bank and yours. It transfers payment information securely whilst protecting sensitive details. This connection lets you offer multiple payment methods and keep payments secure.

What are the main types of payment gateway integration?

The four main types are API integration, hosted payment pages, plugins and extensions, and Payment Links. API integration gives you full control, but it requires developer resources. Hosted pages are quick to set up and handle security for you. Plugins work with platforms like Shopify and WooCommerce. Payment Links let you accept payments without a website. See the comparison table above for a detailed breakdown.

What is the difference between a payment gateway and a payment processor?

A payment gateway collects and encrypts your customer's payment details, whilst a payment processor routes the transaction between banks to complete the payment. The gateway is the front door. The processor is the engine behind it. Many providers bundle both together, so you don't have to manage them separately.

What security standards should a payment gateway meet?

At minimum, your payment gateway should be PCI DSS compliant. This is the industry standard for handling card data securely. Look for features like tokenization, which replaces card numbers with secure stand-ins, end-to-end encryption, 3D Secure authentication, and AI-powered fraud detection. These tools protect your customers and reduce your exposure to chargebacks and fraud.

Sources and references

• https://www.statista.com/outlook/fmo/digital-payments/worldwide

• https://www.bigcommerce.com/glossary/page-load/