FCC & Compliance
A list of telephone numbers that should never appear as the calling number, such as inbound-only government and bank lines, which carriers may block outright.
DNO numbers are numbers whose rightful owner has confirmed they are never used for outbound calls — IRS lines, unassigned or invalid numbers, and inbound-only service desks. Any call presenting one as caller ID is definitionally spoofed.
The FCC explicitly permits providers to block calls presenting DNO numbers, making it the highest-confidence, lowest-false-positive blocking control available.
DNO blocking is cheap, safe, and expected. Not running a DNO list is one of the first weaknesses cited when a mitigation program is judged inadequate.
Presenting a calling number the caller is not authorized to use, in order to disguise the call's true origin or impersonate a trusted party.
The FCC-mandated framework that cryptographically signs calling numbers so terminating carriers can verify the caller ID was not spoofed.
The FCC registry where every voice service provider must file a certification describing its robocall mitigation program.
SipShield scores live SIP traffic with patented AI so the controls behind this term run automatically — and leave the audit trail regulators expect.