T-Mobile US Inc. and AT&T Inc. are offering cross-network call authentication to their customers as part of an ongoing effort to reduce unwanted calls.

The newly implemented SHAKEN/STIR technology helps customers verify whether an incoming call is coming from the number listed on the caller ID display or is a spoofed robocall or scammer. The U.S. Federal Communications Commission has given wireless carriers until the end of the year to voluntarily adopt the SHAKEN/STIR standards. The regulator has also taken steps to make the framework mandatory if the deadline is not met.

In 2018, U.S. mobile customers received nearly 48 billion robocalls, according to the wireless companies' estimates.