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Setting up firewalls correctly is important in ensuring that transactions are processed successfully.

In this section, we provide you all you need to know about how to configure your firewalls while minimising communication errors between your network infrastructure and our payment platform.

Please note that this document presumes that you are already familiar with configuring firewalls, routers or any other device used to block traffic on your network.

Target most up-to-date API base URL

We encourage you to always target the most up-to-date API base URL when sending requests to our platform. Have a look at our dedicated guide for a full overview.

To allow you a smooth transition, previous API base URLs remain available until further notice.

Firewall Port Information

The following table lists the destination ports that must be open to allow communication between your network infrastructure and our payment gateways.

Usage *
  • E-mails from our system to the merchant
Flow from the merchant system’s perspective Incoming Incoming Outgoing
Protocol/port TCP 80 (HTTP)
TCP 443 (HTTPS)**



Merchant system(s) IP address(es)
Destination Merchant system(s) IP address(es) Merchant mail server(s) IP address(es)**** *

Important: All merchant systems communicating with our payment gateways must be able to resolve the public hostname.

* The lists are non-exhaustive.
** Depending on protocols supported by the merchant’s application servers and the merchant configuration in the Merchant Portal and/or hidden parameters (HTTPS recommended).
*** If the merchant maintains a list of IP addresses authorised to send emails on his behalf, our IP ranges should be added to this list. As the owner of a public domain, a merchant could use SPF records, for example, to prevent sender-address spoofing. Please refer to for more information or check with the merchant’s DNS and/or mail server administrator if any action is required.
**** Depending on the merchant’s email system architecture, the server could be hosted by the merchant ISP or inside the merchant's network.

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