Managing the interaction with the merchant website

Two types of URLs are used to manage the interaction with the merchant website:

  • Instant Payment Notification (IPN) URL,
  • Return URL to the merchant website.

Instant Payment Notification (IPN) URL

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

The payment gateway is able to contact the merchant website regardless of the protocol (http or https) that was used.

To process these notifications, the merchant must create a page on his/her website that:

  • analyzes the data received in POST mode,
  • checks that the received information is complete by computing the signature,
  • checks that the notification is not a duplicate (e.g. notification returned from the Back Office),
  • triggers an update of its database (order status, stock status, etc.),
  • sends e-mails to the buyer (invoice, order tracking, etc.).

The processing time directly impacts the delay for displaying the payment summary. 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/her Back Office (see chapter Setting up notifications).

In case of an issue during the 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 Back Office.

Return URL to the merchant website

The merchant can set the "default" return URLs in the Back Office accessible via 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 return 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 redirection URLs).


The status of the "Instant Notification URL" (IPN) rule appears on this screen. If the URL has not been set up, make sure to configure it (see chapter Setting up notifications).