In France, every phone number begins with a digit that reveals a great deal about its nature. The prefixes 01, 02, 03, 04 and 05 designate what are known as geographic landline numbers, regulated by ARCEP (the French electronic communications regulator). Understanding what they mean allows you to immediately assess the likely origin of an incoming call — and therefore how much to trust it.
What is a geographic number in France?
A geographic number is assigned to a subscriber based on their physical address. Unlike mobile numbers (06/07) or VoIP numbers (09), a number starting with 01 to 05 was historically tied to a verifiable location at the time of allocation. ARCEP divides mainland France into five large zones, each associated with a distinct prefix. This architecture dates back to the major French numbering reform of 18 October 1996, when the country switched to ten-digit numbers.
The prefix map: which zone corresponds to which digit?
- 01: Île-de-France — Paris and surrounding departments (75, 77, 78, 91, 92, 93, 94, 95).
- 02: North-West — Normandy, Brittany, Pays de la Loire, Centre-Val de Loire, and some overseas territories.
- 03: North-East — Hauts-de-France, Grand Est, Bourgogne-Franche-Comté.
- 04: South-East — Auvergne-Rhône-Alpes, Provence-Alpes-Côte d'Azur, Corsica.
- 05: South-West — Nouvelle-Aquitaine, Occitanie, and French overseas departments (Martinique, Guadeloupe, Réunion, French Guiana).
Are they still tied to a physical address?
In 2026, the answer is nuanced. Originally, these numbers required a physical telephone line at the declared address. But the growth of VoIP services has gradually blurred this correspondence. It is now possible for a company to obtain a number starting with 01 or 02 without having premises in the corresponding zone, via certain VoIP providers. That said, the allocation conditions remain stricter than for a 09 number. Additionally, number spoofing allows malicious callers to display a fake geographic number — so a 01 number on your screen is not an absolute guarantee of a Parisian caller.
Can you trust a call from 01 to 05?
Geographic numbers generally have a better reputation than 09 numbers because obtaining them requires more steps and leaves a more easily traceable record. They are often used by established businesses, government agencies, doctors, lawyers, and tradespeople. However, commercial canvassing platforms increasingly use these prefixes to appear more credible, and spoofing scams also exploit this trust.
How to check a number starting with 01 to 05
The fastest method is to search the number on TelCheck. The TelCheck community reports in real time any geographic numbers being misused for aggressive canvassing or scams. You can also register on Bloctel (bloctel.gouv.fr) to reduce unsolicited commercial calls, and report any abuse on Signal Conso (signalconso.gouv.fr).
International format and +33 equivalence
In international format, the leading zero is replaced by France's country code, +33. So a Paris number 01 23 45 67 89 becomes +33 1 23 45 67 89 when dialled from abroad. If you receive a call showing +33 1 through +33 5, you are dealing with a French geographic number — legitimately or via spoofing. The same vigilance applies either way.