Caller ID spoofing is how scammers make a call look like it's coming from your bank, your neighbor, or the IRS. Here's how the trick works — and how modern carriers block it at the network edge.
Caller ID spoofing is the practice of falsifying the calling-party number that shows up on a recipient's phone. On IP-based voice networks, the calling number is just a SIP header — anyone with a SIP trunk and a few lines of config can set it to whatever they want. That's how a scam call appears to originate from a local area code, your own carrier, or a government agency.
Under the U.S. Truth in Caller ID Act, spoofing with intent to defraud, cause harm, or wrongfully obtain anything of value is illegal and carries penalties up to $10,000 per violation. The FCC has authority to enforce against both the caller and the originating voice service provider.
Stopping spoofing at the carrier level takes two ingredients: cryptographic authentication of the calling number, plus behavioral analytics on the call itself.
Cryptographically signs and verifies the calling number so downstream carriers can tell whether it was attested.
AI models score every call against dozens of signals — cadence, routing, reputation — to flag spoofing that slips past attestation.
Suspicious calls are rejected at ingress before they ever reach the subscriber's handset.
Spoofed traffic isn't just a subscriber problem — it's a compliance problem. The FCC holds originating voice service providers responsible for the traffic they inject into the U.S. network. If spoofed calls come from your customers and you can't demonstrate reasonable mitigation, you're exposed to forfeitures and RMD removal.
SipShield combines full STIR/SHAKEN signing/verification with patented AI analytics that identify spoofed calls the moment they hit your SBC — and blocks them before they leave your network.