Storing payment credentials for tokenization

You can use our JavaScript Library to allow returning customers to process payments on your app without the need to re-enter all of their card details. Not only does this lead to faster and easier payments for your customers, your business also benefits from not needing to store sensitive card numbers (this can simplify your PCI accreditation process).

This process is called Tokenization.

This document explains how to use an Account check request in order to store the customer’s payment credentials for Tokenization. Account check requests do not debit the customer’s bank account.

 

But if preferred, tokenization can also be performed on previous Authorisation requests, in which the customer has been charged. To do this, you will need the transactionreference of the payment that you would like to repeat, then skip ahead to the Configuration for tokenized payment section of this document, found below.

Prerequisites

• Account Checks are only available for certain acquiring banks. Before you begin, please contact our Support Team and ensure your acquiring bank supports this functionality.
• Account Checks can only be performed for card-based payment methods.

In order to reduce fraud, Visa has mandated that all merchants with a Merchant Category Code (MCC) of 6012 are required to send additional fields in AUTH and ACCOUNTCHECK requests. Click here for further information.

Process overview

Every transaction can be identified by their transactionreference, a unique identifier assigned by Trust Payments. When a new customer orders from your app, you will need to ensure your own system keeps a record of the transactionreference returned.

Your payment request can include the transactionreference from the customer’s previous purchase – or Account check request – to inherit the card number and expiry date for a new purchase (we explain how to do this, below).

The customer will be prompted to enter the security code that is normally found on the back of their card (because we are unable to store this value on our records for security reasons). The customer will need to enter this in order for additional security checks to be performed by the card issuer.

We will then process the transaction, which in all other regards will follow the same process as a standard payment. Ensure your system checks the response JWT to confirm the new payment was processed successfully.

Apple Pay does not support tokenization in this manner.

Configuration for storing of payment credentials

Configure the JWT

You will need to ensure your JWT payload includes the following fields:

Field specification

	Field	Format	Description
	credentialsonfile	Numeric (1)	This must be set to “1”, to indicate the customer agreed for the payment credentials to be stored for future transactions. See below for further information.
	requesttypedescriptions	List	This must be set to [“ACCOUNTCHECK”].

If the credentialsonfile field has been submitted in the request and it is supported by the acquirer processing the transaction, it is returned in the response JWT.

If the parent response indicates an error occurred (errorcode is not “0”), the credential cannot be considered a stored credential, and you must not use these card details in any subsequent payments.

{"payload":{"accounttypedescription":"ECOM","baseamount":"1050","currencyiso3a":"GBP","sitereference":"test_site12345","credentialsonfile":"1","requesttypedescriptions":["ACCOUNTCHECK"]},"iat":1559033849,"iss":"jwt.user"}

About Credentials on File

A stored credential is information (including, but not limited to, an account number or payment token) that is stored in order to process future transactions.

The process of storing credentials for future use is known as Credentials on File (CoF).

Visa and Mastercard have mandated that you must obtain cardholder consent before storing card details for future use, and that these must be flagged at the time of the first authorisation, by submitting the credentialsonfile field in your requests. You must also flag any subsequent payments that are utilising previously-stored credentials, by including the credentialsonfile field in these requests.

Identifying transactions as using CoF provides the following advantages:

• Increases the likelihood of transaction authorisation and settlement.
• Greater transparency and improved experience from the customer’s perspective.
• Issuers are less likely to use the absence of a security code as a reason to decline a transaction.

Handling the response

After the request has been processed, you will receive a single response JWT that contains the response to the ACCOUNTCHECK request. Ensure that the errorcode value returned is “0”, indicating success. Following successful tokenization, you can store the transactionreference in your records. This will be needed later in order to process a new payment with the stored payment credentials. You can also store the maskedpan and paymenttypedescription for purposes of displaying to returning customers when they are choosing their payment method for their next purchase.

Configuration for tokenized payment

Update your payment form

First, you will need to update your payment form to include the additional field fieldsToSubmit.
fieldsToSubmit requires a list containing the value “securitycode”.

Because the customer only needs to be prompted for their security code, the JavaScript will automatically hide the PAN (st-card-number) and expiry date (st-expiration-date) divs. These will not be displayed to the customer.

We have provided an example below as a reference:

<html>
<head>
</head>
<body>
  <div id="st-notification-frame"></div>
  <form id="st-form" action="https://www.example.com" method="POST">
    <div id="st-security-code" class="st-security-code"></div>
    <button type="submit" id="st-form__submit" class="st-form__submit">
      Pay securely
    </button>
  </form>
 <script src=<DOMAIN>/js/v3/st.js></script>
 <script> 
  (function() {
   var st = SecureTrading({  
    jwt: 'INSERT YOUR JWT HERE',
    fieldsToSubmit: [‘securitycode’]
    });  
   st.Components(); 
  })(); 
 </script>
</body>
</html>

Configure the JWT

You will also need to ensure your JWT payload includes the following fields:

Field specification

	Field	Format	Description
	credentialsonfile	Numeric (1)	This must be set to “2”, to indicate the new transaction is using previously-stored credentials.
	parenttransactionreference	Alphanumeric & hyphens (25)	Submit the transaction reference of the previous request from which the card details will be inherited.
	requesttypedescriptions	List	This will need to contain at least the following request types: [“THREEDQUERY”,”AUTH”] Click here to learn more.

{"payload":{"accounttypedescription":"ECOM","baseamount":"1050","currencyiso3a":"GBP","sitereference":"test_site12345","parenttransactionreference":"1-2-345","credentialsonfile":"2","requesttypedescriptions":["THREEDQUERY","AUTH"]},"iat":1559033849,"iss":"jwt.user"}