7 to 10 Digit Dialing Migration for 80+ Area Codes

Published: January 12, 2021

In order to meet the technical requirements for the activation by July 16, 2022 of the new 988 National Suicide Prevention and Mental Health Crisis hotline, a number of US numbering plan areas currently enjoying 7 digit dialing for local calls and also using 988 as a central office code (the 3 digits we dial after the area code) will have to migrate to 10 digit dialing. There is going to be a permissive dialing period during which people residing in towns and cities affected by this change can get used to the new dialing method.

7 to 10 digit dialing transition schedule

• April 24, 2021 - permissive dialing period begins (calls may be dialed using 7 or 10 digits, the latter is encouraged)
• October 24, 2021 - 10 digit dialing becomes mandatory

List of affected NPAs

See official NANPA planning letter for more information (PDF document).