Managing the interaction with the merchant website

Two types of URL are used to manage dialog with the merchant website:

  • Instant Payment Notification, also called the IPN,
  • Return URL to the merchant website (After the payment completed user can be redirected to the merchant web site by passing Return URL parameter in the transaction request, refer below Point number 4 (Optional Fields) with the return URL parameter details.).

Instant Payment Notification - IPN

The payment gateway automatically informs the merchant website about the payment result. The data is sent via POST.

The gateway is able to contact the websites, regardless of the protocol (http or https) that was used.

Notifications are sent from an IP address in the range in Test and Production mode.

To process these notifications, the merchant must create a page on its website that:

  • analyze the data received via POST,
  • verifies the integrity of the received information by computing the signature,
  • makes sure that the notification is not a duplicate notification (e.g. notification returned via the Merchant Back Office),
  • triggers an update of their database (order status, stock, etc.),
  • sends e-mails to the buyer (invoice, order tracking, etc.).

The processing time has a direct influence on the time taken to display the payment summary page. The longer the processing takes, the later the summary will be shown.

To receive notifications, the merchant must set up the notification rules in his Merchant Back Office (see chapter Setting up notifications).

In case of an issue during interaction with the merchant website, the payment gateway sends an e-mail to the shop administrator stating the reason of the error (HTTP error, etc.) and the instructions for returning the notification from the Merchant Back Office.

Return URL to the merchant website

The merchant can configure the "default" return URLs in the Merchant Back Office via the menu Settings > Shop > Configuration tab:

Please only enter the URL of return to the shop in production mode.

Figure 1. Setting up return URLs

By default, the buyer is redirected to the URL regardless of the payment outcome.

If no URL has been set up, the main URL of the shop will be used for redirection (URL parameter defined in the Details section of the shop).

The merchant will be able to override this setting in his/her payment form (see chapter Setting up return URLs).


The status of the rule "Instant payment notification at the end of payment" (IPN) is displayed in this view. If the URL has not been set up, make sure to specify it (see chapter Setting up notifications).