HTML form fields

The HTML form will contain the following four hidden fields:

HTML Form Hidden Fields Table
Field Name Description


This lets our system know the version of our messages you are using (the current version is 4.00).


This lets us know which transaction type you wish to perform. In most cases this will be PAYMENT.


This is your unique identifier, assigned to you by Opayo during sign up.


This is a field containing encrypted and encoded details of the transaction. It prevents the customer from tampering with the contents of orders before they are submitted to us. Learn more about how to construct the Crypt fie