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Payment API guide for successful online transactions

Payment API guide for successful online transactions

Payment APIs are what ensure your business processes online transactions quickly and securely.

We have complete FasterPay API references you can refer to for the technical requirements.

But to explain this for everyone without coding knowledge, you can read our guide into how they work for your business and will grow your sales.

What are payment APIs

An API (application programming interface) is, putting it into layman terms, a written instruction that lets two devices, databases, or applications to connect and share information.

So, this means payment APIs are for managing payments on an e-commerce website. So there are the likes of a:

  • Debit order collection API: You can connect your front-end system to a bank for all your debit order collections and reconciliations.
  • Mobile bill payment API: Again, connect using your system to cover payments across a wide variety of mobile billing and transactions.

These all let your business process credit card payments, track customer orders, and keep customer lists.

An example of this is if you buy tickets for a show through a third-party events organizer. Here the API will enable the communication between the performers and the event organizer.

So, this means you can process your payments with the store’s connected payment gateway.

Along with the above, a payment API will also provide your business with:

There are also some APIs that will allow street side stores to take payments at a terminal or with a smartphone.

Basically, there’s a lot of flexibility available and that’s one of the main reasons why your business should look to use APIs.

How are payment APIs used?

There are many reasons why payment processing APIs are in such widespread use for online businesses. These include:

  • To provide a streamlined checkout experience that delivers a range of payment options for your customers’ various needs.
  • So your business can go global and reach customers in distant markets, all without having to rely on banks in other countries.
  • Stopping data entry errors. For example, when bank account details are being typed. Instead, by connecting to other APIs in the network you avoid any issues.
  • Getting instant settlements and improving the cash flow for merchants by reducing transaction risks.
  • Fraud risk reductions and improvements to your security through payment authentication features (plus all-important customer compliance checks).
  • Getting access to reports with data on the nature of all your transactions.
  • Making regulatory compliance for PCI, AML, and KYC much simpler.

As you can see, there are many uses for the technology. But there’s also a lot of terminology to get to grips with.

It’s worth doing this so you can ease your transition into understanding common terms.

Payment API terms

Getting used to APIs can be tricky, especially if you have no coding experience or aren’t technically savvy.

Below we break down some of the common terminology that’ll help you understand how payment APIs work behind the scenes.


An application programming interface, which uses protocols for accessing computer data.

Access control

These are systems that allow authorized users to view and change certain information.


A primary account number—this is the main credit card number.


This is the Payment Card Industry Data Security Standard. These are the industry standards that all finance businesses must follow, including credit card processors.

For a payment processor such as FasterPay to operate, we need to comply with PCI DSS. Which, of course, we do!


These are security system secrets that are used for customer authentication and verification.

How does a payment API work?

A payment processing API will complete the following processes:

  • An application transmits a message (or request) to the API.
  • This is relayed to the payment processing network.
  • The network processes the request and responds to the API.
  • The API then relays a response to the application.

All of this makes it much easier for a browser to pass transaction details to you—the merchant.

APIs will also empower your brand to take customer payments from apps, eCash, bank transfers, and many other APMs.

The benefits of payment APIs

Payment APIs will connect a checkout system to a payment network. So, what are the benefits of a business doing this? Let’s take a look.

  • Better user experience: The customer purchasing experience is greatly improved as there’s no longer a time-consuming checkout form.
  • Lower churn rates: You’ll increase your payment acceptance rate as fewer customers drop out of the process due to payment frustration.
  • Simplicity: The payment process is also greatly simplified, speeding up transactions and helping to scale your business’ sales.
  • Future-proofing: By using the latest technology, you’re ensuring your business is meeting customer expectations. This ensures you’re able to scale up your business with the future in mind—keeping you competitive for the long-term.
  • Flexibility: Manage a wide range of different transactions with various payment types.

Simply put, by integrating the technology you’re ensuring you future-proof your brand and offer your customers the ways they want to pay.

By taking innovative steps to streamline your online payments, you’re putting your business into a strong position to remain competitive.

Choosing the best payment processing API for your business

There are many APIs available, so your business has to look out for the one that suits your needs.

One of the most important considerations is how easy the payment API will be to integrate into your system. For example, if you’re adding a debit order collection API or mobile bill payment API, then you need to make sure you have the capability to add them to your checkout.

So, what’s a good API and what should it provide to you? Let’s take a look.

Clear and insightful documentation

You should have access to detailed documentation explaining about the API and how to integrate it into your website.

For it to be great and helpful for you, this needs to be comprehensive in its details. And it should be updated frequently to keep you on top of developments.

For example, our reference documentation at FasterPay is updated when we make changes to our APIs. And we have extensive guides taking you step-by-step through the how to integrate it into your website.

The API should also follow an accessible, consistent, and logical structure. And there should be noticeable error messages when something has gone wrong.

This’ll help you speedily get the software up and running, minus any hitches.

API client libraries

These are useful as they can speed up the build process. The library will let you access copy and paste versions of code samples.

And they’ll be in programming languages such as PHP, Java, and Ruby. So, this’ll save you a great deal of time and hassle when integrating complex code into your site.


Considering how long the API is operational for is important. Is it available for when you need it to be?

Your provider’s communication

The best providers are transparent and offer excellent communication for you to stay in the know.

It’s important to keep on top of your operational performance and how your business will adapt to future changes.

This means transparency is essential as if the provider has issues, you need to know as soon as possible to sort out the issue.

Customer support

Business is 24/7 in the digital era, so you need the best service whenever you face any technical issues.

At FasterPay, we offer 24/7 customer support from a dedicated global team.

This can be by phone or email, whichever step is necessary to discuss the issue you’re facing.

High security standards

As a user, you should find it easy to change/rotate API keys (and other credentials) for reasons such as restricting access.

This may be to ensure devices can only read data, rather than altering it.

You’ll also want exceptional levels of data encryption to prevent any data breaches. You can read about FasterPay’s security measures in our guide.

Updates and versioning

You need to understand whether updates to the API will lead to further tech issues on your end.

Will the integration stay steady? Is there a streamlined transition? Make sure you determine this process with your provider.

API testing

Find out if the API provider has a test environment/sandbox where you can use dummy data and try out the various features of the integration.

This can help to remove bugs before you launch your new API, or make any changes to it.

FasterPay’s payment API simplifies your payments

All you need to do is create a free FasterPay business account now and get started right away. The app is available on:

If you have any questions about our API, get in touch with our 24/7 customer support team: