When your phone rings, the nature of the displayed number — geographic landline, mobile, VoIP or premium-rate — gives you valuable information about the probable identity of the caller and the associated risks. This guide explains how to distinguish each type of number and what that distinction means in practice.
Geographic landlines (01 to 05)
Numbers starting with 01, 02, 03, 04 or 05 are geographic landlines assigned by ARCEP across five regional zones. They are generally associated with companies, public bodies or individuals with a physical landline. Their geographic deployment and higher acquisition cost make them broadly more trustworthy. However, spoofing allows fraudsters to fake the caller ID and display any landline number. A high TelCheck score therefore remains essential to confirm a caller's legitimacy.
Mobile numbers (06 and 07)
The 06 and 07 prefixes designate French mobile lines. The 06 prefix has existed since the inception of mobile telephony in France, while 07 was progressively assigned from 2010 onwards to address the saturation of 06 ranges. Mobile numbers are legitimate in the vast majority of cases, but they are also used by canvassers who buy entire ranges of 07 numbers at low cost for their outbound calling campaigns.
VoIP numbers (09)
Numbers starting with 09 are non-geographic numbers assigned to internet telephony (VoIP) services. They are billed as local calls from landlines and included in most mobile plans. Their very low acquisition cost and ease of obtaining in bulk make them the preferred numbers for commercial canvassing platforms. A call from a 09 number should therefore be treated with caution, even though many legitimate companies also use them for their switchboards.
Premium-rate special numbers (08xx)
The 08 range includes numbers with specific pricing regulated by ARCEP. Key prefixes to know:
- 0800: freephone numbers — free from a landline.
- 0806, 0809: local call rate.
- 0810 to 0820: shared cost, generally a few cents per minute.
- 0890 to 0893: premium-rate, between €0.15 and €0.80 per minute.
- 0897 to 0899: heavily premium-rate, up to several euros per minute.
Receiving a call from an 08xx number is not suspicious in itself — many legitimate customer service lines use these numbers. However, calling back a 0899 or 0897 without checking can be very costly.
The practical difference in terms of risk
As a general rule, landline numbers (01–05) present the lowest baseline risk, followed by mobile numbers (06–07). VoIP numbers (09) warrant more caution, especially for unsolicited calls. Premium-rate numbers (0897–0899) should only be called back after checking on TelCheck. Unknown foreign prefixes (+222, +252, etc.) present the highest risk.
Always check on TelCheck regardless of the number type
A number's type gives clues but is not a guarantee. Spoofing can hide the true nature of a fraudulent call behind an apparently legitimate number. TelCheck (telcheck.fr) gives you the real reputation based on community reports, independent of the displayed prefix.