Southern California Numbering Plan Area 909 will get an overlay code starting in February 2021. Area code 909 currently serves parts of San Bernardino, Los Angeles, Orange and Riverside counties. The new area code 840 was approved on June 13, 2019 by the California Public Utilities Commission (CPUC).
There will be a transition period during which local and toll calls within existing NPA 909 will be dialed using both 7 or 1+10 digits, the latter dialing method being recommended. The purpose of this transition AKA permissive dialing period is to get residents of this area accustomed with 1+10 digits dialing which will become mandatory with the introduction of the new overlay area code.
- July 25, 2020 – permissive 1+10 digit dialing begins for telephone calls between numbers in area code 909
- January 23, 2021 – mandatory 1+10 digit dialing begins
- February 23, 2021 – new area code 840 enters service
See official NANPA announcement (PDF document)