Communication of 26 June 2026 on the Royal Decree of 12 May 2024 to combat international voice calls with spoofed Belgian telephone numbers

CLI spoofing, the manipulation of the telephone number of the calling line, is a big problem with a negative impact on Belgian citizens and businesses.

For this reason, the Royal Decree of 12 May 2024 to combat international voice calls with spoofed Belgian telephone numbers has already been introduced.

The legislation raises questions from the sector regarding the concrete, practical implementation.

This communication aims to answer these questions.

It first outlines the current situation, then it examines a particular case.

The RD stipulates that it is the task of the operator receiving the international incoming call via its international network interface to take the appropriate measures to block such calls.

The principle is that the operator, with a SIP or SBC server on Belgian territory and being the first to receive the fraudulent call from abroad from a SIP or SBC server located abroad, blocks the fraudulent international incoming call.

The particular case discussed in this communication are transit calls, or calls made from Belgium to Belgium but with routing via infrastructure located abroad.

To ensure that this traffic is still considered as national traffic, the operator has to keep the national and international traffic strictly separate.

This is done by routing international incoming traffic via a dedicated circuit that is entirely controlled by the operator with whom the call was initiated.