Verizon started rolling out a free service on Thursday to help wireless customers combat robocalls.

The wireless carrier also announced it has begun deploying technology on its network that verifies calls are authentic and not from fraudsters.

The free version of “Call Filter” allows Verizon customers to receive alerts when a call is likely spam, automatically block robocalls based on a preferred level of risk, and report unsolicited numbers, Verizon said.

Verizon offers a paid version of Call Filter that can identify unknown callers by name, among other additional features, for $2.99 per month.

The service is available to all postpaid wireless customers with a compatible device, though it could take about three weeks before it’s available to all customers with devices that qualify, a spokesperson said. Verizon customers can enroll here or through the Call Filter app, which is pre-loaded on most Android phones and some Blackberry devices, and can be downloaded on iPhones in the Apple App Store.

The rapid rise of robocalls has been driven in part by caller ID “spoofing," in which scammers place calls that appear to come from local numbers or legitimate businesses. Nearly half of all mobile calls this year will come from scammers, according to First Orion, an Arkansas-based call management company.

Verizon also announced that is has begun deploying technology that lets consumers know that incoming calls are actually from the owner of the number listed on a caller ID.

The technology is called STIR/SHAKEN, which stands for the Secure Telephone Identity Revisited (STIR) and for Signature-based Handling of Asserted information using toKENs (SHAKEN), and is a protocol for authenticating phone calls.

In January, T-Mobile announced that it was the first carrier to implement the call authentication system.

Last week, AT&T and Comcast said that they expect to authenticate customer calls later this year.