47 C.F.R. § 64.6303

(a) Except as provided in §§ 64.6304 and 64.6306, not later than June 30, 2021, a voice service provider shall either:

(1) Upgrade its entire network to allow for the initiation, maintenance, and termination of SIP calls and fully implement the STIR/SHAKEN framework as required in § 64.6301 throughout its network; or

(2) Maintain and be ready to provide the Commission on request with documented proof that it is participating, either on its own or through a representative, including third party representatives, as a member of a working group, industry standards group, or consortium that is working to develop a non-internet Protocol caller identification authentication solution, or actively testing such a solution.

(b) Except as provided in § 64.6304, not later than June 30, 2023, a gateway provider shall either:

(1) Upgrade its entire network to allow for the processing and carrying of SIP calls and fully implement the STIR/SHAKEN framework as required in § 64.6302(d) throughout its network; or

(2) Maintain and be ready to provide the Commission on request with documented proof that it is participating, either on its own or through a representative, including third party representatives, as a member of a working group, industry standards group, or consortium that is working to develop a non-internet Protocol caller identification authentication solution, or actively testing such a solution.

(c) Except as provided in § 64.6304, not later than December 31, 2023, a non-gateway intermediate provider receiving a call directly from an originating provider shall either:

(1) Upgrade its entire network to allow for the processing and carrying of SIP calls and fully implement the STIR/SHAKEN framework as required in § 64.6302(e) throughout its network; or

(2) Maintain and be ready to provide the Commission on request with documented proof that it is participating, either on its own or through a representative, including third party representatives, as a member of a working group, industry standards group, or consortium that is working to develop a non-internet Protocol caller identification authentication solution, or actively testing such a solution.

[87 FR 42946, July 18, 2022, as amended at 87 FR 75944, Dec. 12, 2022; 88 FR 40118, June 21, 2023; 90 FR 40256, Sept. 18, 2025]