What is what area code is 628?

The 628 area code is an overlay area code for the 415 and 628 area codes in California, United States. It covers the northeastern part of the San Francisco Bay Area, including the cities of San Francisco, Oakland, and Berkeley. The overlay was created in 2015 to provide additional numbering capacity for the region. Callers in the 628 area code must now dial the full 10-digit phone number (area code + number) for all calls, even local calls within the same area code.