When the North American Numbering Plan become created by using AT&T in 1947, the a long way northern a part of California received area code 916, with the exclusion of the town of Sacramento, which used location code 415. California place codes have been reorganized geographically in 1950, in order that 916 turned into assigned to a numbering plan vicinity that comprised handiest the northeastern element from the Sierra Nevada to the Central Valley. The coastal region to the west was assigned vicinity code 415. With this variation, Sacramento became additionally modified to area code 916.

On March 1, 1959, numbering plan area 415 turned into divided in a flash-cut (with out permissive dialing period) wherein the northern part of the numbering plan region (Solano County and north thereof) acquired location code 707, which was California's eighth region code (together with 213, 415, 916, 714, 408, 805, and 209), and the last new location code inside the kingdom till 619 become added in 1982.

707 Area Code

It isn't only the handiest this kind of region codes never to have required relief, however it's also the most effective considered one of California's 13 authentic-layout area codes (i.E., region codes with a 0 or 1 as their center digit, the others being 310, 510, 818 and 909, all of which, in addition to 619, had been delivered decades after 707's debut) now not to require relief from a "new layout" area code (those with 2–eight as their middle digit, which had been added beginning in 1995 whilst the NANP ran out of the original format NPAs), in spite of explosive increase within the location, specifically its southern component, as well as the proliferation of mobile phones and pagers.

When location code 530 was split from vicinity code 916 on November 1, 1997, the Dixon location was renumbered from region code 916 to 707 and switched from the Sacramento local get admission to and transport vicinity (LATA) into the San Francisco LATA.

In 1999, a 3-way, two-segment split of the area code 707 become scheduled with the aid of Pacific Bell,[1] such that a new place code (627) would have served maximum of Napa and Sonoma Counties and small portions of Marin and Mendocino Counties, at the same time as some other new location code (369) could have served Solano County, as well as a small portion of Napa County, starting in December 2000 and October 2001, respectively. However, because of the achievement of range pooling in retaining numbering resources, the California Public Utilities Commission cancelled these moves on July 27, 2000. infotakeaway

Prior to October 2021, region code 707 had phone numbers assigned for the primary office code 988. In 2020, 988 turned into targeted nationwide as a dialing code for the National Suicide Prevention Lifeline, which created a warfare for exchanges that allow seven-digit dialing. This vicinity code became therefore scheduled to transition to ten-digit dialing with the aid of October 24, 2021.[2]