PRESS RELEASE: First anti-spoofing measures in force from 1 June

Prague, 26 April 2024 – CTU has issued an amendment to General Authorisation No. VO-S/2/07.2005-10, which sets out the conditions for the provision of public communications networks and associated facilities, as amended. The amendment, designated as General Authorisation No VO-S/2/04.2024-1, sets out two new conditions for the provision of public communications networks and for the provision of electronic communications services. The new conditions aim to reduce the impact of fraudulent spoofing.

The first condition, effective from 1 July 2024, will ensure that at the points designated for connecting calls from abroad to the Czech Republic, analysis shall  be done on how the calling party is identified in the signalling message of a call coming from abroad. The analysis shall assess whether the subscriber is not identified by a certain type of so-called Czech number (with a +420 area code) and if so, the call will not be connected. The condition does not currently apply to mobile numbers that may be roaming and calls from abroad marked with such a number may be perfectly legitimate.

The second condition is related to the insertion of information about the calling subscriber into the signalling message and targets primarily calls that originate in the Czech Republic. The addition sets out the rules for what information (telephone number) the operator may insert in the signalling message to identify the calling party. Compliance with the condition should ensure that this marking always contains a real telephone number linked to a specific subscriber or electronic communications service and can be called back. This shall prevent situations where a meaningless indication is given. This condition is effective from 1 June 2024.

CTU will continuously evaluate the effectiveness of the new measures. CTU expects that these regulatory measures for fixed numbers will be appropriately complemented by self-regulatory measures on the part of mobile operators, which, in mutual cooperation thereof, should effectively minimise attacks abusing Czech mobile numbers.

Tereza Meravá
Spokesperson
Czech Telecommunication Office