A map of Illinois telephone area codes, including the newest code, 464, which will be added to the existing 708 area. North American Numbering Plan Administrator SHARE ...

OAKLAND — The new telephone area code for a big stretch of the East Bay, including its largest city, Oakland, is 341, state regulators said Thursday.

That means callers in 82 area codes will need to dial the recipient’s area code first before adding their usual phone number. After Oct. 22, local calls made with just seven digits may not connect.