Payment application program interfaces (APIs): What they are, different types and their benefits for businesses


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  1. Introduction
  2. What is an API?
  3. What is a payment API?
  4. Types of payment APIs
  5. How do payment APIs work?
  6. Benefits of using payment APIs
    1. Stripe’s payments APIs

Payment APIs are reshaping the way that businesses manage customer transactions. Businesses that adopt payment APIs report a significant increase in transaction speed and a decrease in payment processing errors. According to a recent McKinsey study, one-third of businesses that implement payment APIs expected to see a 10% increase in revenue.

As more businesses shift their operations online, protecting sensitive financial data has become a larger concern. Payment APIs offer robust security features and help businesses to maintain necessary compliance standards, mitigating the risk of data breaches. Additionally, with the feature-rich environment that these APIs provide, businesses gain flexibility and control over their payment processes, allowing them to offer diverse payment methods and handle complex payment scenarios.

Thanks to the numerous advantages that they bring, it's clear why businesses are turning to payment APIs. Below, we'll cover the key features of payment APIs, as well as how they operate and how businesses can best use these tools to enhance their transaction handling capabilities.

What's in this article?

  • What is an API?
  • What is a payment API?
  • Types of payment APIs
  • How do payment APIs work?
  • Benefits of using payment APIs

What is an API?

"API", which stands for "application programming interface", is a set of rules and protocols for building and interacting with software applications. APIs are integral to modern software development and are used widely in distributed systems, web services and cloud computing.

APIs define the methods and data formats that software components use to communicate with each other. They serve as a type of contract between different software components, stipulating how those components interact. Not only do APIs allow different software systems to communicate with each other, but programmers can also use them to access the functionality of other software components. For example, a weather application might use a weather service provider's API for current weather data.

Different types of APIs exist, including web APIs, operating system APIs and library-based APIs, among others. When people talk about APIs, they are generally referring to web APIs, which are built around HTTP and can return data in formats such as JSON or XML. Web APIs provide the interface between different web services and applications, enabling them to communicate with each other over the internet.

What is a payment API?

A payment API is a specific type of API that allows software applications to process payments. These APIs provide a secure and reliable way for applications to interact with a payment processing service, enabling actions such as:

  • Processing payments
    An application can use a payment API to send payment details – such as credit card information and the transaction amount – to a payment gateway or a credit card processing service.

  • Storing payment details
    Some payment APIs allow an application to store payment details for future transactions. This is how services like Amazon or Netflix remember your credit card details and let you make payments with one click.

  • Refunding transactions
    If a customer wants a refund, the application can use the payment API to reverse the transaction.

  • Handling subscriptions and recurring payments
    Businesses can use payment APIs to set up and manage recurring payments for services like subscriptions.

  • Verifying payments
    Payment APIs can verify whether or not a transaction was successful.

Typically, payment APIs are designed with strong security measures to protect sensitive data, such as credit card numbers. For example, they can employ techniques such as tokenisation, in which sensitive data is replaced with a non-sensitive equivalent, referred to as a token, which has no extrinsic or exploitable meaning or value.

Types of payment APIs

There are several types of payment APIs, which are often categorised based on their specific functionalities. Here are a few examples:

  • Transaction APIs
    These are used to carry out payment transactions. They support functionalities such as initiating, refunding or cancelling payments.

  • Subscription APIs
    These APIs are used for handling recurring payments, which are an important part of subscriptions. They allow businesses to bill customers automatically, at regular intervals.

  • Tokenisation APIs
    These APIs allow for the secure storage of payment information. They replace sensitive payment data, such as credit card numbers, with a non-sensitive equivalent, known as a token.

  • Payout APIs
    These APIs are used to send payments to individual accounts. Often, marketplaces or platforms use these APIs to send payments to sellers or service providers.

  • Preauthorisation APIs
    These APIs allow for the temporary holding of funds on a customer's card. This can be useful for situations in which a business needs to verify a customer's ability to pay before providing a service or shipping a product.

  • Data and reporting APIs
    These APIs provide access to detailed data and analytics about payment transactions, which can be useful for understanding trends, monitoring performance and making informed business decisions.

Different payment service providers offer different sets of APIs with varying specific functionalities. Stripe, for example, provides APIs that developers can integrate into their applications to handle payment transactions. We'll discuss Stripe's API capabilities further below.

How do payment APIs work?

Payment APIs serve as a bridge between a business application and the payment gateway, enabling businesses to manage a range of payment operations efficiently and securely. The exact functionality of a payment API can vary depending on what role it's intended to play. Here's a general overview of how they work:

  • Transaction initiation: The process begins when a customer decides to make a purchase. The customer inputs their payment information, such as credit card details, into your application, which could be a website, mobile app or other platform. This information is transmitted securely to your server.

  • API request: Your server, which has been integrated with a payment API, sends a secure HTTPS POST request to the payment gateway's API. The request includes the necessary transaction details such as the payment method, card details and transaction amount.

  • Payment processing: Upon receiving the request, the payment gateway processes it, which entails interacting with various entities including card networks and issuing banks to validate the transaction details, check for potential fraud and execute the transaction. After handling this complex interaction, the payment gateway delivers a simple response to your server.

  • API response: The payment API's response to your server includes details such as whether the transaction was approved or declined, a transaction ID and other relevant information. If the payment is successful, the payment gateway also ensures that the transaction amount is transferred from the customer's bank to your merchant account.

  • Transaction confirmation: Upon receiving the response from the payment gateway, your server processes it. If the transaction is successful, your application typically updates its own records to reflect the purchase and communicates a confirmation to the customer.

Aside from assisting in individual transactions, payment APIs provide several additional functionalities:

  • Tokenisation
    To enhance security, many payment APIs provide a tokenisation feature with which they replace sensitive payment data (such as credit card numbers) with a unique identifier or token. This significantly reduces the risk associated with storing sensitive customer data.

  • Subscriptions and recurring payments
    For businesses with a recurring billing model, payment APIs automate this process. They securely store the customer's payment information and process charges at set intervals.

  • Refunds and disputes
    Payment APIs offer businesses an efficient way to handle refunds and manage disputes with minimal manual input.

  • Reporting and analytics
    Payment APIs can provide businesses with transaction data and analytics, offering insights into sales trends, successful and failed transactions and dispute rates.

  • Payouts
    Payment APIs can enable businesses that operate marketplaces or platforms to send payments to other users' bank accounts.

Benefits of using payment APIs

Payment APIs are an important tool for businesses, especially those conducting transactions online, because they streamline operations, strengthen security measures and provide enhanced flexibility. Let's explore these benefits in more detail:

  • Security and compliance
    Payment APIs enhance the security of your transactions. These APIs use secure encryption methods to protect data and maintain compliance with the Payment Card Industry Data Security Standards (PCI DSS), which reduces the potential risk of data breaches and fraud. Some APIs even provide tokenisation, replacing sensitive data such as credit card numbers with a unique identifier or token, which mitigates risk in case of a breach.

  • Simplified payment processing
    Businesses can use payment APIs to simplify the way that they accept and process payments. Payment APIs handle the complex aspects of dealing with financial institutions and card networks as well as fraud detection.

  • Speed and efficiency
    Payment APIs enable automation, increasing the speed of processes that might otherwise require extensive manual effort. They can facilitate real-time payments, process bulk transactions, manage refunds and handle subscription renewals, thus enhancing operational efficiency.

  • Multicurrency and international payments
    If your business operates internationally, payment APIs can manage currency conversion and international transactions, simplifying the process of conducting business globally.

  • Versatile payment options
    With payment APIs, businesses can accept a wide range of payment methods. This includes credit and debit cards, digital wallets, and bank transfers, thereby improving customer experience by allowing customers to use their preferred payment methods.

  • Improved cash flow management
    Payment APIs provide real-time visibility into your transactions, which makes it easier for you to manage your cash flow. With immediate access to payment data, you can accurately track revenue, refunds and declines, which can lead to more informed financial decision-making.

  • Data insights and reporting
    Many payment APIs offer data and analytics capabilities. They provide insights into sales trends, successful transactions, failed transactions, dispute rates and more. These insights can be vital for business strategy and decision-making.

  • Scalability
    As your business grows, so does your transaction volume. Payment APIs are designed to handle large volumes of transactions, which allows you to scale your business without worrying about your payments infrastructure.

  • Integration and customisation
    You can integrate payment APIs with existing business systems, such as CRM, ERP and accounting software. Payment APIs also allow you to customise the checkout experience, enabling you to provide a seamless user experience that aligns with your brand.

Stripe's payments APIs

Stripe offers comprehensive suites of APIs that you can use to manage a wide range of payment-related tasks. Stripe's APIs are designed to simplify the way businesses accept and manage online payments, which allows for seamless integration with existing business operations and provides robust security measures.

Here's how Stripe's payment APIs function:

  • Payment processing
    Stripe's payment API enables businesses to accept payments from a variety of methods including credit cards, debit cards and digital wallets such as Apple Pay or Google Pay. Stripe's APIs take care of the entire payment process, from transaction initiation to funds settlement.

  • Subscriptions and billing
    Stripe offers APIs for handling subscriptions and recurring billing. Businesses can manage and automate their recurring revenue, including free trials, upgrades, downgrades and cancellations, directly through the API.

  • Connect platform
    Stripe Connect is an API designed specifically for marketplaces and platforms. It allows businesses to accept payments and pay out to third parties, whether they're service providers, contractors or vendors.

  • Radar for fraud management
    Stripe Radar's API uses machine learning to identify and prevent fraudulent transactions. It evaluates every payment across Stripe's global network of businesses to detect patterns and identify fraud.

  • Reporting and analytics
    Stripe provides an API for generating financial reports and analytics. Businesses can access real-time insights into their financial data and use the API to sync transaction data with their accounting software.

  • International payments
    Stripe supports over 135 currencies, allowing businesses to accept payments from customers all over the world. This makes it easier for businesses to scale internationally.

Stripe's APIs enable businesses to create a customised payment process that suits their specific needs, improving efficiency and customer experience while reducing the risk of fraud. The API-first infrastructure also makes it easy for businesses to add new features or payment methods as they become available, which ensures that the payment process can grow and adapt with the business. To learn more and get started, go here.

The content in this article is for general information and education purposes only and should not be construed as legal or tax advice. Stripe does not warrant or guarantee the accurateness, completeness, adequacy, or currency of the information in the article. You should seek the advice of a competent attorney or accountant licensed to practice in your jurisdiction for advice on your particular situation.

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