Caller ID spoofing
Caller ID spoofing — and how to stop it.
Spoofing is how scam calls appear to come from a bank, a government agency or a local neighbor. Here's how it works and how modern carriers block it at the edge of their networks.
The problem
What is caller ID spoofing?
Caller ID spoofing means presenting a calling number you aren't authorized to use. On IP networks the calling number is simply a value in SIP signaling, so anyone with access to a trunk can set it to almost anything — a local area code to look familiar, a bank's fraud line, or a government hotline.
In the United States, the Truth in Caller ID Act makes it unlawful to transmit misleading or inaccurate caller ID with intent to defraud, cause harm or wrongfully obtain anything of value, and the FCC can pursue both the callers and the providers whose networks carry the traffic. Not every altered caller ID is illegal — legitimate businesses may show a main number — which is why intent and authorization matter.
The defenses
How carriers block spoofed calls
Stopping spoofing takes both cryptographic proof and behavioral judgement.
STIR/SHAKEN
Signs and verifies the calling number so downstream networks know whether, and how strongly, the originator vouched for it.
Do Not Originate
Blocks calls presenting numbers that should never place outbound calls, plus invalid and unallocated numbers.
Behavioral analytics
Scores cadence, routing and reputation to catch spoofing that slips past attestation — for example C-attested gateway traffic.
If you're a carrier, spoofing is a compliance problem
Spoofed traffic doesn't just annoy subscribers. The FCC holds originating and gateway providers responsible for the traffic they put onto the U.S. network. If spoofed calls trace back to your customers and you can't show reasonable mitigation, you face tracebacks, enforcement and potential removal from the Robocall Mitigation Database.
VoIP Radar combines STIR/SHAKEN signing and verification, DNO screening and real-time analytics to identify spoofed calls the moment they reach your SBC — and stop them before they leave your network.
Get in touch
Find out where your network stands
Tell us about your switch and traffic. A VoIP Radar engineer will map your STIR/SHAKEN, RMD and fraud exposure and send a written assessment — free, within one business day.
- STIR/SHAKEN & attestation review
- RMD certification gap check
- Fraud & robocall exposure snapshot
- Deployment plan for your SBC / softswitch