Payment APIs explained: What merchants need to know

If you’re researching payment APIs, you might be experiencing the following: 

• You're tired of managing multiple payment providers. Handling integrations with four payment service providers (PSPs), three different digital wallets, and solutions like Buy Now, Pay Later is a logistical nightmare. Each one has its own integration process, security updates, and data formats, draining your engineering team’s time and resources.
• You're frustrated by slow, inefficient processes. Your team is forced to patch together different systems, wasting time and risking mistakes in handling payments that could be streamlined.
• You're overwhelmed by the thought of scaling your payment operations. Whenever you consider expanding to new markets or adding new payment methods, you’re held back by the complexity of integrating more systems. Reworking your entire payment infrastructure is a daunting prospect that seems impossible with your current resources.

Payment APIs are integration tools that connect your payment systems with other services or technologies. While they simplify the integration process, their effectiveness in managing payment operations, enhancing customer experiences, or improving security depends on how they are implemented and the overall infrastructure supporting them.

In this article, we’ll run you through what you need to know about payment APIs, how to determine your company's best payment API provider, and what infrastructure will let you make the most of payment APIs. 

We’ll cover:

• What you need to know about payment APIs
• What is a unified payment API, and why should you use one?
• Why choose Primer for your unified payment API?
• How Primer’s unified payment API helped speed up Dabble’s international expansion
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If you’re ready to start simplifying your payments infrastructure with a unified payment API solution, contact Primer today. 

What you need to know about payment APIs

An application programming interface (API) enables the interoperable data exchange between different computer systems, allowing them to communicate and share functionality seamlessly.
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For example, you could use an API request to connect your team’s email inbox to your team’s customer service ticket software, so every time you receive an email with a customer problem, a new ticket is automatically created with the customer’s name and the contents of their email. In this case, the API transfers the email data to your ticket software. 

Before APIs, integrating payment systems was a slow, rigid, and resource-intensive process. Businesses had to rely on custom-built connections, which required extensive coding and ongoing maintenance. Adding a new payment provider or scaling to new regions often meant starting from scratch, significantly delaying deployments and limiting flexibility.

Payment APIs have transformed this process by enabling systems to communicate directly and efficiently. Here’s how a payment API typically works in an online checkout process:

1. A customer selects items on an ecommerce website, adds them to their cart, and proceeds to checkout.
2. The website collects payment details, like card information and the total amount, and sends this data to a payment API.
3. The API forwards the payment request to the payment processor’s system, which validates the transaction—checking the card details, ensuring sufficient funds, and confirming security compliance.
4. The payment processor returns the result to the API, indicating whether the payment was successful or failed (e.g., insufficient funds or invalid details).
5. The API relays this response to the website, which displays the outcome to the customer (e.g., “Payment successful” or “Payment failed”).

What to look for in a payment API

All good payment APIs should provide the following: 

• Agnostic and easy integration: The API should be platform-agnostic, easy to integrate, and require minimal technical setup to quickly enable new payment processors or methods.
• Reliability and uptime: High uptime, reliability, and consistency are non-negotiable, ensuring that your payment systems remain operational.
• Scalability: A robust payment API should seamlessly handle spikes in payment volumes, scaling to meet the needs of growing businesses.
• Security: Given the sensitive nature of payment data, the API provider must demonstrate strong security protocols, including measures to mitigate risks like data breaches.
• Data efficiency: The back end should allow you to access the payment data you need with minimal friction, supporting efficient operations and reporting.
• User experience: The front end should prioritize a smooth transaction experience, avoiding clunky workflows like separate windows, pop-ups, or multiple forms.
• Developer support: Comprehensive documentation, SDKs, and accessible developer support are essential for reducing integration time and resolving issues quickly.
• Low latency: Minimal latency ensures faster transactions, improving customer experience and operational efficiency.
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However, you will still face the challenge of having to set up separate integrations for each payment API, such as:

• Each payment API will require individual implementation and must be configured to integrate with your system.
• Each PSP and API will have different release times for when they need to be upgraded.
• They will each have different security and data requirements.
• They will all send different information back, which you’ll need to consolidate on the backend. 
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As businesses scale and face increasing complexities in their payment operations, many are turning to unified payment solutions. By consolidating their payment stack with a single API integration, they can streamline access to and management of all their payment services, simplifying operations and improving efficiency.

What is a unified payment API and why should you use one?

A unified API consolidates multiple services, applications, and data sources under a single interface. Instead of developers needing to work with various individual APIs—each with unique authentication methods, data formats, and endpoints—a Unified API provides a standardized way to interact with different services. This simplifies integration, reduces development time, and allows for easier maintenance.

If we imagine payment APIs are the airlines, a unified payment API is like an airport. It manages and maintains relationships with all the airlines, helping passengers reach their destinations.

A unified payment API doesn’t directly handle the movement of funds—much like an airport doesn’t “fly the planes.” Instead, it facilitates connections between merchants and payment processors, helps select the best payment routes, and ensures these relationships are managed efficiently.

Six reasons you should consider using a unified payment API 

A unified API serves as a gateway, offering a single point of integration to connect and manage multiple Payment Service Providers (PSPs) and payment types. It provides centralized control, allowing users to streamline payment operations, optimize routing, and analyze performance—all within one platform.

Here are six reasons to use a unified payment API: 

1. Simple integrations mean using fewer engineering resources

Instead of building and maintaining separate integrations for each payment processor, a unified API requires only one integration, significantly reducing development time and simplifying setup. Adding new payment providers or types becomes a matter of days rather than months.

2. Easier maintenance through managed updates

Keeping multiple single APIs up to date with security patches, compliance changes, and new features is time-consuming and error-prone. A unified API manages these updates centrally, reducing the workload and reducing errors.

3. Flexibility and scaling to keep up with your markets

With a unified API, you can quickly add new payment methods or providers as your business grows without impacting existing integrations. This flexibility allows you to respond faster to changing customer demands and expand into new markets seamlessly.

4. Payment routing with a much easier setup

Even the simplest payment routing setup demands significant engineering resources without a unified API, and the complexity only grows as you add more providers, payment types, and regions. A unified API simplifies this process by reducing the need for extensive engineering work. Centralized control streamlines integration and empowers you to optimize payments, improve success rates, and select the best route for every transaction—all from one platform.

Learn more: Payment routing: Everything you need to know

5. Standardized data and reporting from centralized data

Working with multiple APIs means dealing with different data formats, complicating reporting and analysis. 

A unified API standardizes your payment data, making tracking and analyzing payments across all channels easier. You can get a clearer view of your operations with much less effort, as the information you need is in one place and format. 

6. Consistent customer experience

A unified payment API can offer a consistent API design and developer experience by standardizing resources and data models across various payment APIs. This makes it easier for internal payment managers to put together payment routes but also ensures a consistent payment experience for customers, helping increase checkout conversion rates. 

When does it make sense to implement a unified payment API?

Although it may be tempting to wait until payments get very complex before using a unified payment API, starting very early will save time and headaches down the road. As soon as you have to manage more than one PSP—which should be on day one—it makes sense to start searching for a unified payment API provider.

Why choose Primer for your unified payment API?

Primer is a unified payment infrastructure platform that gives companies the tools they need to optimize payment performance and unlock new revenue opportunities within payments. 

With a single integration through our unified API, Primer empowers merchants to:

• Access hundreds of payment providers, payment methods, and fraud prevention services without the need for additional integration work.
• Build and manage powerful workflows with no-code tools to optimize payment performance and reduce costs.
• Gain full visibility into payment performance across all your payment services, unlocking valuable insights to enhance operations.

Here are three reasons to use Primer: 

1. Integrate with hundreds of payment processors instantly – no extra development needed

One clear benefit of unified APIs is that they make it easy to connect with multiple payment processors. At Primer, we’ve taken this a step further to enable anyone to add a PSP without any code. With Primer, you can integrate with a new provider and activate it almost at the click of a button.

Here’s how:

• Go to Primer’s dashboard and click “Integrations.”
• Select the “+ New Integration” button and search from the hundreds of providers Primer supports.
• Once you find your desired provider (e.g., Worldpay), follow these simple steps:
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  • Provide Primer access to your processor account using your company’s API credentials.
  • Add your merchant account information.
  • Select the payment types you want to support from the provider.

Once configured, you can immediately build a Primer Workflow to route payments to Worldpay—or any other PSP—easily.

With Primer.io, adapting to market shifts becomes effortless. You can instantly add new payment methods or acquirers as you expand into new regions without complex integration overheads. This agility empowers you to stay competitive, offering customers the payment options they expect wherever they are while keeping your operations streamlined and scalable.

This is exactly why Pelago chose Primer’s unified API for its payments infrastructure. Pelago, a booking platform connected to Singapore Airlines, serves over 150 countries, connecting travelers with unique experiences abroad. As they expanded across APAC markets, they needed an API solution that could simplify integration with multiple PSPs and enable localized payment options for their customers across Asia.

“Market fragmentation means no single processor can offer comprehensive coverage and performance,” explained Altaf Dhamani, Pelago's Chief Product Officer. Primer’s unified API provided the answer. “As an infrastructure layer, it solves our challenge by allowing us to use various payment services without the painful process of directly integrating with them.”

By leveraging Primer’s unified API, Pelago reduced the complexity of managing multiple integrations and improved the payment experience for their customers across APAC.

Read the full case study: Pelago creates new horizons for travel and payments with Primer.

2. Use Workflows to improve payment outcomes and customize flows without coding

Working with multiple payment APIs often means manually building workflow logic and transaction mapping, a process that is resource-intensive and prone to errors—especially when making changes. Primer eliminates this complexity with its Workflow tool, allowing you to create payment flows with clicks, not code.

With Primer’s Workflow features, you can:

• Simplify payment routing: Set up logic to route transactions based on customer location, PSP performance, or cost efficiency.some text For example, you can create a flow that routes UK transactions through one PSP and French transactions through another to optimize performance and reduce costs.

• Retry failed payments automatically: Use Fallbacks to route failed transactions to a backup provider, ensuring fewer payment disruptions. For example, say you want to add a backup PSP for transactions through a UK acquirer. You can create a flow that triggers when your preferred UK processor fails. Primer ensures that all customer data is transferred to the fallback PSP, and your payment system will automatically try to complete that customer’s transaction. 

• Trigger specific actions: Automate processes like sending notifications, issuing refunds, or updating internal systems based on payment outcomes.
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Once set up, Primer’s Workflow tool takes over, automatically ensuring each transaction is routed and processed according to your logic. This reduces manual intervention, saves time, and helps improve payment success rates.

Read more about our drag-and-drop workflows and what they can do for you in our documentation. 

3. Analyze and improve payment performance with centralized payments data 

Many payments and finance teams must spend much time interpreting and standardizing data from different providers in different formats.

With Primer, you get a complete view of your payment data through our Observability Dashboard. By standardizing PSP data models, Primer delivers consistent, real-time insights. Instead of deciphering varied decline reasons, Primer maps transaction results uniformly—while still providing access to raw data when needed.

The Observability dashboard provides a clear view of payment trends and detailed insights from top-performing processors to individual transactions.

For example, you can view your historic online payments by currency, processor, refund rate, card network, BIN numbers, 3DS authentication, payment gateway, chargeback rate, and more. This ability to quickly scan your data will help you spot potential problems and improvements. 

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Primer also offers a Monitor feature, which will send you notifications if certain parameters are exceeded or if a metric falls outside of the expected range. This can improve your response time and alert you to anything unusual before problems escalate.

These are just a few ways Primer can help you improve your payment processes. For a full consultation on how Primer can help you better your payment infrastructure, contact us today. 

How Primer’s unified payment API helped speed up Dabble’s international expansion

Dabble is a betting app that integrates with Primer to help better manage their payment strategy. Early on, they knew getting payment processing right would be the difference between success and struggle. 

Anthony Cugnetto, Head of Product—Core at Dabble, explained: “The challenge was utilizing payments as a catalyst for business growth while minimizing the overheads and complexities associated with expanding a payment stack."

That’s why they prioritized finding a payment solution and started using a unified payment API to deal with complexity early on. This meant their team didn’t waste any resources trying to build payments expertise and could instead focus on improving the core function of their social betting app. 

Primer allowed them to scale domestically and expand internationally without adding the burden of complexity onto their payments or dev teams, so they could move as fast as their business was moving. That meant they could capitalize on opportunities and expand quickly without drowning in work to update payment flows.

"Our initial aim was to simplify managing and expanding our payments stack," Anthony explains. "Primer enables just that. With a single integration, we have total control over our end-to-end payment flows. And, crucially, without utilizing developer resources, we can add new payment methods and processors, scale into new markets, and change our payment routing and logic on the fly."  

Thanks to Primer, they were able to:

• Maintain a 96% authorization rate during a huge spike in payment volume before the 2023 Melbourne Cup.
• Recover over $70,000 (AUD) in revenue in just a month via Fallbacks
• Reached number four in the app store’s sports betting and daily fantasy category six months after launching in the US.
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Learn more about how Dabble used Primer to solve their payment problems and launch internationally: Dabble picks a winner by partnering with Primer. 

Use a unified payment API like Primer to take full control of your payments

Lowering complexity in your payment processes is a key goal for anyone managing more than a couple of payment service providers and payment types. Payment APIs start a simpler payment infrastructure, and unified payment APIs take that to the next level.

At Primer, we’ve built on top of a unified payment API to give you all the functionality of a unified system but have gone even further to add additional tools to see your data more clearly and build payment options without code. Contact us today if you’re ready to level up your payment processes.