What Is an API Payment Gateway?

Even after you have set up your online shop, you cannot start trading until you have a payment gateway, as this is crucial to your ability to accept and process card and other types of electronic payments from your customers.

There are two options to consider when setting up your payment gateway. You can either have your payment service provider (PSP) host your payment page on their site or you can directly integrate the payment page into your own website so that your customers stay on your site as they complete the checkout process.

If you go for the latter option, this is where API payment gateways will come in. An API (application program interface) is a set of instructions that will help a developer access a software program or tool. A payment gateway API is a set of lines of code which will integrate the payment gateway into the backend of your shopping cart.

Pros and Cons of Choosing an API Payment Gateway

Here are some of the reasons why you might consider choosing an API payment gateway:


  • It allows for greater flexibility and gives you full control over your customers’ checkout experience.
  • Because your customers don’t have to leave your website to complete the payment process, they are more likely to remember your site and go back to it to shop again.
  • You can design and brand your payment page to make your checkout process seamless, and manage all the processes involved in-house.

An API payment gateway is not the best choice for everyone however. Here are a couple of reasons why it might not be the best option for you:


  • Setting up the API will require a certain level of technical know-how. If you don’t have the skills to do it yourself, you’ll need to hire a web developer who can.
  • The responsibility for PCI-DSS compliance is in your hands, which constitutes an additional expense.

The Best API Payment Gateways

If you do decide to use an API payment gateway for your online shop, you can take a look at our list of the best ones in the market in order to decide which qualities you’re looking for in your payment gateway.


paypal logo

PayPal offers a payment gateway API called Direct Payment as part of its Website Payments Pro merchant services package, which is available for £20 a month, plus transaction fees.

The Direct Payment API is already integrated into a number of shopping carts, but it does come in a toolkit that you can easily integrate into your website. This API allows transactions to be sent online over Secure Socket Layer (SSL), the standard encryption method for online transactions.

It gives you the ability to flag suspicious payments and has an API certificate to let you make calls to the API through a secure connection.

For more information about PayPal’s services, read our PayPal review.


stripe logo

Stripe is a unique payment gateway in that it comes in the form of different APIs to suit a wide range of platforms, including PHP, Ruby, Java and Python. Stripe takes pride in the completeness, scalability and cleanness of its APIs which give users intuitive interfaces for customising their checkout process.

The Stripe payment gateway can be easily integrated into ecommerce platforms such as Shopify and BigCartel. It also allows integration into ERP systems and offers seamless integration with its mobile apps for iPhones and Android phones.

Stripe has a simple pricing structure with no monthly fees and a fixed rate of 2.4% plus 20p per transaction.

More information can be found on our page reviewing Stripe payment services.


braintree logo

Braintree is another payment gateway that is purely API-based. A division of PayPal, one its main features is that you can start accepting PayPal payments (and attract its 148 million customers) simply by adding a few lines of code to your user interface.

Its software development kit (SDK) is designed to be compatible with iOS and Android (for mobiles) as well as JavaScript (for the web) and provides a secure payment processing platform.

Braintree’s pricing structure is comparable to that of Stripe, with no monthly fees and just a fixed rate of 2.4% plus 20p for every transaction.

Next Steps: Save your business money

BMa only works with the UK’s top payment gateway and merchant account providers to ensure you get the best bang for your buck.

Compare free price quotes, save up to 30% on costs and build a long-term, mutually beneficial relationship today. Just fill in the form to get started.