A spoofed number is a falsified caller ID: the caller deliberately transmits someone else's number — a bank, a government agency, your CFO's mobile — so the call appears to come from a trusted source. Spoofing exploits the fact that caller ID was designed for convenience, not authentication.
How caller ID spoofing works
Caller ID is self-reported by the originating system. VoIP services let callers set any outbound number, and commercial spoofing services make it point-and-click. Frameworks like STIR/SHAKEN attest that a call's number is legitimately used, but coverage is incomplete — especially internationally — so a familiar number on screen still proves nothing.
How to tell if a number is spoofed
- You can't, reliably, from the display alone — that's the point of the attack.
- Behavioral tells: the "bank" asks for credentials or codes; the "executive" demands urgent secrecy; callbacks to the displayed number reach someone with no knowledge of the call.
- The only dependable test: hang up and dial the person or institution back on a number from your own records. See call verification methods.
My number is being spoofed — what to do
If strangers call you back about calls you never made, your number is being used as a disguise. You can't stop it directly (the spoofer never touched your account). Practical steps: record a voicemail noting the spoofing, report to your carrier and regulator (FCC in the US, or your national equivalent), and expect it to fade as campaigns rotate numbers within days or weeks.