2. Your server builds a Confirmation Page

Your server-side script will build an order confirmation page, displaying the full details of the purchase to the customer, including their billing and delivery addresses, basket contents, total order value, and contact details.

This script will also place an HTML form on that page with the action set to the Opayo Form registration page.

When the customer clicks Pay Now on the form, the hidden fields are POSTed to Opayo and customer’s browser is redirected to our hosted payment pages.

The Opayo system begins by validating the Crypt field contents by first checking to ensure all required fields are present and that their formats are correct. If any required fields are not present or contain the wrong data type, a generic validation error will be displayed on your screen. The full error detail can be obtained by looking under the ‘Invalid’ tab of the ‘Transactions’ screen within MySagePay.

This normally happens only in the development stage, so your customers are unlikely to encounter this page.

If all fields are present and correct, the information in those fields is then validated. The VendorName is checked against our database and the Currency of the transaction is validated against those accepted by your merchant accounts. The VendorTxCode is checked to ensure it has not been used previously, the Basket/BasketXML contents are validated to ensure they have been sent in the correct format, and the Amount field is validated. These validation checks ensure you have passed appropriate values.

If everything in the POST passes the validation checks, the transaction is registered with the Form system and a new transaction code is generated. This code, the VPSTxId (or Transaction ID), is our unique reference to the transaction and is sent back to you at the transaction completion stage.

Related Information

❮ Back to The customer orders from your siteThe customer enters payment details on Opayo’s server ❯