The 415 Area code serves the Bay area of San Francisco and some of its surrounding areas. It has a single overlay of area code 628 that serves the same area.
Main cities of Area code 415/628 are San Francisco and the surrounding areas. Other cities where 415/628 serve together includes Brisbane, Belvedere, Daly City, Corte Madera, Larkspur, Mill Valley, Fairfax, Novato, Ross, San Anselmo, San Rafael, Sausalito, Tiburon.
This area code comes under the Pacific time zone.
This Area code is one of the original three area codes of California. In 1947, When the North American Numbering Plan (NANP) introduced by AT&T for Bell system & Operator Toll Dialing in the state of California . The state divides into three different geographical zones and assigned the Area codes to meet the telephonic needs.
- The area code 916 assigned to the southern part.
- The area code 415 assigned to the central part.
- The Area code 213 assigned to northern part of the state.
Split of 415 Area code
With the passage of time the progress made in technology, because of population growth and to meet the high demands of more telephone numbers. For this the area code 415 has splits three times.
- In 1959, to create the 408 area code for San Jose, the South Bay, the Monterey Bay, and the Salinas Valley.
- In 1991, to create the 510 area code for the East Bay, including Oakland.
- On August 2, 1997 to create the 650 area code for San Francisco county, San Mateo County, San Francisco Golf Club, Brisbane and Daly City.
Currently the area code 628 is serving within the same area as an overlay of 415.
415/628 Area Code
Because cof rapid increase in economic growth and telecommunication demands The California Public Utilities Commission (CPUC) had approved an overlay plan On December 14, 2014, to fulfill the requirement of more telephone numbers in the 415 area code region. So, On March 21, 2015, the overlay became effective with the issuance of new 628 area code that was overlaid onto the 415 area code.
Dialing procedure in an overlay
In an overlay the existing customers allows to retain their phone numbers and 415 area codes. The 415/628 overlay might cause the change in dialing procedures, making ten-digit dialing compulsory in the area.
What is Ten-digit dialing?
In Ten-digit dialing procedure the area code+ telephone number dialed to make a call inside or outside the local area. Sometimes, the ten-digit numbers prefixed with number 1 (trunk code). This is common in areas where overlays implemented. 10- digit dialing format, when necessary, looks like this 1+ area code+ telephone number. This is also called national format.
- To avoid any interruption during calls, do not forget to dial 1 before area code. Otherwise, your call may be disconnected or instructed to hang up or call again.
- Cellphone callers link with certain cell service providers may be able to complete calls without dialing “1” before the area code.
- Call rates remains same in an overlay area with any dialing procedure.
- Dialing 1 + area code + 7-digit telephone number does not mean the change in call. The local call remain the same and call cost does not affect after the overlay.
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