Your phone rings. The screen shows your bank's number — matching exactly the one on the back of your card. You answer with confidence. But the person on the other end is a fraudster. This is phone spoofing: a technique that falsifies the caller ID displayed on your screen. In 2026, it is one of the most widespread phone scam techniques in France.
What is phone spoofing technically?
With VoIP protocols — especially SIP, on which virtually all internet-based calls rely — the sender can freely choose the "From" field value, i.e. the number displayed on the recipient's screen. There is no mandatory authentication mechanism for this value in the standard protocol. Online platforms offer this spoofing service for a few tens of euros per month.
How fraudsters use it in practice
- Banking number impersonation: displays your bank's official number to extract an SMS code or transaction approval.
- Official number impersonation: CPAM (3646), tax authority, CAF, police — an official number suppresses the natural reflex of suspicion.
- Local number impersonation: a number with your regional prefix increases the chance you will answer.
Caller ID is not proof of identity
The displayed number does not guarantee the caller's identity. It is information the sender chooses to transmit, and it can be falsified. Initiatives such as STIR/SHAKEN aim to address this vulnerability, but deployment in France remains partial in 2026.
Signals that betray a spoofed call
- Artificial urgency — act within minutes or face consequences.
- A request for the SMS code you just received — no legitimate institution does this.
- Being discouraged from hanging up and calling your bank directly.
- Being asked to approve a transaction in your banking app "to block it".
The absolute rule: hang up and call back yourself
Hang up, wait two minutes, then call back on the official number you find yourself — on the back of your card, in your app, on service-public.fr or ameli.fr. Check the displayed number on TelCheck (telcheck.fr) and report suspicious calls on Signal Conso (signalconso.gouv.fr).