Arcep has published a draft decision amending the framework for the allocation and use of numbering resources, and submitted it for public consultation.

In particular, this draft amendment aims to strengthen the fight against number theft and to incorporate the provisions of Law No. 2025-594 of June 30, 2025, on preventing fraud involving public aid.

Reinforced measures against number fraud

Article L. 44, IV of the Post and Electronic Communications Code requires operators to implement a caller number authentication (CNA) mechanism to verify that the caller ID matches the number to which it is assigned. This mechanism, which is now widespread, allows the origin of fraudulent calls to be identified after the fact.

Despite this system, Arcep has identified numerous cases of mobile number spoofing, especially through the fraudulent use of the “local breakout” routing mode, which allows certain international calls to be routed via a French mobile number without French operators being able to verify its authenticity.

To close this loophole, Arcep states that when operators identify an international call with a French mobile number that has not been authenticated, they will replace the number with the generic identifier “99 99 99 99 99”. The Authority also recommends using this identifier in cases where technical limitations prevent the transmission of authentication data. Lastly, it intends to clarify the obligation for originating operators to verify the calling numbers they use by requiring them to contractually specify the list of numbers their customers are authorized to use as calling numbers and to technically restrict calls to this list.

A new category of numbers dedicated to the public interest

The text also introduces a new category of multipurpose numbers for general interest communications, in accordance with Article 16 of the June 30, 2025, law. These numbers, reserved for organizations designated by a ministerial order, may be used by automated call and message systems, overriding the general prohibition set out in the code. The aim is to ensure the protection of certain essential communications, such as alert messages. To achieve this, Arcep plans to allocate specific prefixes in mainland France (01 51 0, 02 81 0, 03 41 0, 04 41 0, 05 41 0, and 09 41 0), as well as suitable series in overseas territories.

More efficient resource management and enhanced consumer protection

In addition to these modifications, the draft decision provides for a complete ban, effective from July 1, 2028, on the transfer of numbers between operators. It also includes measures aimed at improving the efficient use of numbering resources, such as requiring operators to assign at least one number to an end-user within one year of allocating a block. Finally, to protect end-users and prevent bounced calls to highly overused short numbers, a gradual ban on using these short numbers as caller IDs is planned, starting in July 2027.