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.

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 their website that:

  • analyzes 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 it takes to display the payment summary page. The longer the processing takes, the more the summary display will be delayed.

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 via the Merchant Back Office.

Return URL to the merchant website

In the Merchant Back Office, the merchant can configure the "default” return URLs via the menu Settings > Shop > Configuration tab:

Figure 1. Setting up return URLs

The merchant can set up a different return URL for each mode.

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

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 "Instant Payment Notification at the End of Payment" (IPN) rule is displayed in this window. If the URL has not been set up, make sure to specify it (see chapter Setting up notifications).