T-Mobile, AT&T and Verizon have taken steps to reduce spoofed scam calls

They've all implemented the FCC's STIR/SHAKEN protocol that verifies a caller's true number.

Yuri Gripas / reuters

All three major US carriers have met the deadline to implement the FCC's new anti-spoofing protocol designed to protect users from scam caller impersonation. Both Verizon and T-Mobile announced yesterday that all calls originating on their networks are 100 percent compliant with the FCC's "STIR/SHAKEN" technology designed to show a caller's true phone number. AT&T, meanwhile, confirmed with The Verge that it's also in compliance with the new rules.

The FCC had set a deadline of June 30th for the major carrier's to implement the STIR/SHAKEN protocol developed under the Ajit Pai regime. For now, smaller carriers have until June 30th, 2023 unless the FCC decides to shorten that timespan, something that's currently under consideration.

The STIR/SHAKEN standards serve as a common digital language used by phone networks, allowing valid information to pass from provider to provider which, among other things, informs blocking tools of possible suspicious calls.

So what does the new protocol do? Without it, scam or spam callers can spoof their phone numbers to show up as local numbers, making it more likely that you'll pick up. STIR/SHAKEN deals with that by using public key encryption digital certificates sent by the originating telephone service provider, with the keys verified by the terminating service provider. If everything matches, then the calling number hasn't been spoofed.

The FCC is hoping that carrier implementation will reduce the volume of spam, scam and robocalls that have made answering your phone a game of whack-a-mole. The commission said that over 1,500 voice providers have filed to be in its robocall mitigation database with over 200 of those being fully certified. "Beginning on September 28, 2021, if a voice service provider’s certification does not appear in the database, intermediate and voice service providers will be prohibited from directly accepting the provider’s traffic," the FCC stated.

The protocol will help reduce but not totally eliminate scams or robocalls. Legacy phone systems that don't use IP protocols are exempt from the rules, and the system won't work with international calls. Still, if a local pops up on your phone going forward, you can have more confidence that it's not a fake number coming from a scammer.

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