Masked, private, or unknown: what's the difference?
In France, when a call arrives with no caller identification, your phone may display "numéro masqué" (masked), "numéro privé" (private), or "numéro inconnu" (unknown). The first two generally mean the caller deliberately hid their identity by dialling #31# or enabling the option through their carrier. The third can simply mean the network didn't transmit the information.
Can you unmask a hidden number?
For an ordinary member of the public, the honest answer is no. No consumer app can reliably reveal a masked number. In France, only a judicial requisition can compel a carrier to identify an anonymous caller.
What to do and how TelCheck helps
Let it ring — a legitimate caller will leave a voicemail or follow-up SMS. Block all masked calls on iPhone via Settings → Phone → Silence Unknown Callers, or through the Phone app settings on Android. Because masked numbers are invisible by definition, TelCheck cannot look them up directly. Register with Bloctel (bloctel.gouv.fr) for broader protection, and report confirmed scam attempts on Signal Conso (signalconso.gouv.fr).