New Revision of the Numbering Plan in France

ARCEP has released a new update of the French National Numbering Plan, which will come into force on 1 January 2026 (with certain provisions taking effect at later dates). This update follows the series of adjustments made by ARCEP since 2018 and aims to modernize the framework governing the allocation and use of numbering resources, while incorporating the new requirements introduced by the Act of 30 June 2025 on combating fraud involving public aid.

The key measures adopted by ARCEP are as follows:

Strengthening the fight against caller ID spoofing

In response to the continued rise in caller ID spoofing—despite the authentication mechanisms introduced in recent years— ARCEP is strengthening the rules applicable to operators. Several thousand reports filed in 2025 via the “I alert ARCEP” platform prompted the French regulator to implement new measures:

1. Masking of the caller’s number when an unauthenticated call using a French mobile number is made from abroad.
   Unlike the initial proposal, which considered displaying a generic number (“99 99 99 99 99”), the final version requires masking the number to avoid confusion while still allowing calls to be completed.
2. Masking of the number when authentication information cannot be preserved.
   This measure was also adjusted compared to the draft submitted for consultation: ARCEP now requires that even when technical constraints prevent full transmission of authentication data, the original signature must be preserved to ensure traceability.
3. Strengthened rules governing the verification of numbers used by customers.
   Whereas the public consultation framed this as a recommendation, the final decision makes it mandatory for operators to contractually define the list of numbers each customer is permitted to use and to technically restrict usage strictly to this list.
   This obligation is intended to prevent any unauthorized use of a number from the moment a call is initiated.

Creation of a new category of numbers for public-interest purposes

Under the Act of 30 June 2025, ARCEP is creating a dedicated category of numbers for automated calls and messages related to public-interest missions. These numbers may only be assigned to entities designated by a joint order of the ministers responsible for consumer protection and electronic communications.

Strengthened management of numbering resources in the French overseas territories

To address increasing pressure on numbering resources in several overseas territories, ARCEP is introducing new measures, including the allocation of additional number blocks, improved use of existing ranges, and the creation or expansion of ranges tailored to local demand.

Additional measures to protect users

1. Stricter rules on the use of high-rate short numbers as caller IDs.
   ARCEP confirms the prohibition on using such numbers above certain tariff thresholds, while specifying in the final version that this measure will take effect on 1 July 2027, giving operators and service providers sufficient time to adapt.
2. Temporary freezing of numbers after termination before reassignment.
   This measure - particularly relevant in cases of technical line closures (for example, during copper switch-off)- is confirmed: numbers are frozen for a defined period, allowing the former user to request recovery before they can be reassigned.

Operators must now update their processes to comply with these new obligations.