Identifying an unknown mobile number is no longer just a reflex of curiosity. Since August 11, 2026, unsolicited telemarketing is prohibited in France: a commercial call from a number you do not recognize now constitutes a potential signal of illegality.
At the same time, Arcep requires operators to mask the caller ID when an international call displaying a French mobile number cannot be authenticated. These two developments change the way we interpret an unknown call and the relevant tools to respond to it.
Comparison of methods to identify an unknown number
Not all solutions are equal. Their effectiveness depends on the type of number received (landline, mobile, hidden, spoofed international) and the current French legal framework.
| Method | Identifiable number type | Cost | Main limitation |
|---|---|---|---|
| Google reverse search | Landline, mobile (if published online) | Free | Ineffective on unindexed or unlisted numbers |
| Reverse directory (Pages Jaunes, 118 712) | Landline, mobile (if listed) | Free or paid depending on the service | Limited coverage to consenting subscribers |
| Third-party app (TrueCaller, Orange Phone) | Mobile, landline, some identified spam | Freemium | Community database, not exhaustive |
| Direct contact with the operator | Hidden number (upon justified request) | Free | Reserved for cases of harassment or threats, lengthy procedure |
| Reporting to DGCCRF / SignalConso | Illegal telemarketing | Free | Does not reveal the caller’s identity to the user |
Reverse searching via a search engine remains the first reflex, but its effectiveness drops as soon as the number belongs to a private individual not listed in a public directory. Community apps partially fill this gap by relying on reports from other users.
You can learn more about Le Petit Rat Porteur to delve into the good reflexes to adopt when faced with an unknown mobile number.
Numbers hidden by the operator: what Arcep’s filtering changes
A number displayed as “unknown” or “private” no longer automatically means that the caller has chosen to hide their line. Arcep mandates the masking of unauthenticated international calls displaying a French mobile number. A legitimate roaming correspondent can therefore appear without an ID, just like a fraudulent call with a spoofed number.
This measure aims to reduce the spoofing of French mobile numbers from abroad. However, it creates a gray area for the user: it is impossible to distinguish, at the time of the call, a contact on the move from a scam attempt.
Three clues allow for sorting afterward:
- A voicemail left by the caller remains the most reliable signal. A telemarketer or a robot generally does not leave one.
- An immediate callback from the same hidden number, without a message, suggests a prospecting automated system.
- A follow-up SMS mentioning an identifiable company allows for verifying the legitimacy of the call via the official website of that company.
For recurring hidden numbers that fall under harassment, the only recourse is to contact the operator with a documented call history. The operator can then forward the information to the authorities, but will not directly communicate the number to the complainant.
Telemarketing banned since August 2026: consequences for unknown calls
The law of June 30, 2025, which came into effect on August 11, 2026, established an opt-in regime for commercial telemarketing. A company must obtain explicit, prior, traceable consent limited to one year before contacting an individual. Fines can reach €75,000 for an individual and €375,000 for a company.
At the same time, Bloctel, the opposition registry for telemarketing, was hacked and permanently closed on August 11, 2026. This closure increases the risk that previously protected numbers will be targeted by fraudulent campaigns.
If you receive an unsolicited commercial call from an unknown number, two actions are possible:
- Report the call on the SignalConso platform of the DGCCRF, specifying the number, date, and content of the exchange.
- File a complaint if the caller identifies as a company: the burden of proof of consent rests with the professional.
This legal framework changes the very nature of the unknown call. Before August 2026, an unrecognized number could be an annoying but legal telemarketer. Now, any commercial call without prior consent is an offense.
Native filtering on iPhone and Android: settings to activate
Mobile operating systems include filtering functions that reduce unwanted calls without installing additional apps. Their effectiveness depends on the chosen configuration.
On iPhone, the “Silence Unknown Callers” feature (Settings > Phone) sends any call from a number not in the contacts, recent history, or Siri suggestions directly to voicemail. The risk is missing a legitimate call from a doctor, delivery person, or tradesperson.
On Android, the Google Phone app offers anti-spam filtering that can be activated in the caller ID settings. It relies on a database fed by community reports and displays a real-time warning when a number is listed as unwanted.
Native filtering does not replace identification. It prevents the ringing but does not reveal who is behind the number. For active identification, third-party apps like TrueCaller or Orange Phone cross the incoming number with their databases and display a name or category (spam, business, individual) even before you pick up.
The combination of native filtering and third-party apps covers most cases. Filtering blocks numbers already identified as spam, while the app attempts to identify those that slip through the filter.
With the closure of Bloctel and the new legal framework, the responsibility for filtering shifts to the user and the tools embedded in their phone. Activating these settings takes only a few seconds, and systematically reporting suspicious calls on SignalConso helps feed the databases that protect all subscribers.
