Phone Number Geolocation (France Only)

Geolocation allows us to pinpoint the position of an object, such as a telephone, on the Earth's surface with a certain degree of precision.

— Landline phone: the location corresponds to the address to which the line is connected.

— Mobile phone: the target is the device's current position. Several technologies can be used for this purpose: cell tower signals, GPS satellites, or other systems (Bluetooth, Wi-Fi, etc.).

— International number: the country associated with the SIM card can be identified. This does not necessarily indicate where the call was made from, but it does provide an indication of its administrative origin.

French phone numbers are semi-structured and use a double geographic code, the first with the numbers from 01 to 05, which delimit 5 main regions in France but also and ZABPQ sub-codes (around 500) which are used to locate a geographic area close to the original location of the landline number.

There are several ways to try to identify who owns a phone number, but results vary depending on the type of number and the privacy level of the line. Here are the main options:

— Search in a reverse directory

Some online services allow you to enter a number to obtain information about its owner, if the owner is registered and has agreed to be included in the directory:

— Search on a search engine

If the number has been published on a website or forum, or if it is associated with a professional or business, or if it has been reported as suspicious on specialized sites.

— Check if it is linked to an account on an app

Some apps can reveal the identity associated with a number:

WhatsApp/Telegram/Signal: By adding the number to your contacts, it is sometimes possible to see a photo, name, or status, depending on the person's privacy settings.

— Use community directory apps

Apps like TrueCaller or Sync.Me aggregate information from data shared by users and can provide the name associated with a number if it has been identified by others (this raises privacy concerns).

— Contact the carrier

Telephone companies do not share subscriber information for privacy reasons. This is unless a complaint is filed (harassment, fraud, etc.) within a legal framework, with the intervention of judicial authorities.

The 5 regions are distributed as follows:

01: Paris and Paris region

02: North West of France

03: North-east of France

04: South-east of France and Corsica

05: South West of France

The French territories of the Atlantic Ocean are in 05 and the Indian Ocean in 02.

Link to ARCEP Open Data resources: here

For international calls, a prefix system has been put in place to identify each country. USA is +1, United Kingdom is +44.

With antenna-based geolocation, the phone's position is estimated by analyzing the signal strength received from several nearby antennas.

GPS, on the other hand, relies on a set of orbiting satellites that send signals to calculate precise coordinates, often to within a few meters.

In both cases, at least three different sources are required to determine a position by triangulation: it's the cross-referencing of these data that calculates the device's location.