JavaScript Library

If you have already integrated using version 2, upgrading to version 3 requires minimal development work. Click here to view the migration document.
- Legacy documents for version 2 can be found here.
- Click here for migration documentation for version 1.


Use the resources below to learn how to configure your checkout to accept credit / debit cards:
• How to test your solution
• List of supported card payment methods
• Transaction life-cycle
• Payment flows and additional request types
• Capturing card details on your own form
• Tokenization


Apple Pay is a wallet-based mobile payment service by Apple Inc. that lets users process payments using an iPhone, iPad or Mac. Customers benefit from a familiar and streamlined checkout experience, where their billing information can be pre-filled, ready for purchase. Use the resources below to get started:
• How it works
• Establish a connection with Apple Pay
• Configure your solution
• How do I customise the Apple Pay button?
• Managing Apple Pay transactions

An Account Check request allows a card to be validated by checking the cardholder’s first line of address, the cardholder’s postcode and the security code, to ensure the details entered by the customer are valid. A unique transactionreference is returned in the response, which can be used to reference the customer’s payment credentials when making future purchases, without the need to store them on your own system. Read the below to learn more:
• What are Account Checks?
• Using Account Check to verify customer’s details
• Storing payment credentials for tokenization

Configure your checkout to schedule recurring payments that are processed automatically on your behalf. Read the below to learn more:
• Learn about our Subscription Engine
• What are Scheme Updates?
• Schedule a subscription with immediate payment
• Schedule a subscription with a free trial
• Managing your subscriptions using MyST
• Configuring subscription notifications

Use the resources below to help you accept payments in different countries:
• Localisation
• What is Dynamic Currency Conversion (DCC)?
• Processing Dynamic Currency Conversion (DCC) payments
• How do I test Dynamic Currency Conversion (DCC) payments?
• Can I update Dynamic Currency Conversion (DCC) payments?
• How do I refund Dynamic Currency Conversion (DCC) payments?
• How do I use my own Dynamic Currency Conversion (DCC) provider?
• Can Subscriptions be performed using Dynamic Currency Conversion (DCC) payments?
• List of supported currencies

Protect Plus is a sophisticated counter-fraud service that provides your site with an extra layer of security against fraudulent transactions. It makes use of the industry’s largest negative database to perform a comprehensive suite of fraud assessments, including identity checks against the UK electoral roll and BT databases. Read the below to learn more:
• What is Protect Plus?
• How do I precede a payment with a Risk Decision?
• How do I follow a payment with a Risk Decision?
• How do I test my Protect Plus integration?

MyST is our online interface where you can search for and manage transactions processed on your account. The resources below explain how to use MyST to manage transactions processed through your checkout:
• Getting started with MyST
• Search for transactions
• View transaction details
• Perform actions on transactions

Using our Webservices API, your system can be configured to perform back-office requests without the customer present. The resources below explain how to use MyST to manage transactions processed through your checkout:
• Getting started with our Webservices API
• View transaction details
• Update transaction with new data
• Refund transaction
• Process Payout
• Process new card payment
• Learn more about our Webservices API

After you have finished configuring your site and have tested thoroughly, follow these final steps to begin processing live payments:
Credit / debit cardsEnhanced Post