North American Numbers Source-cited · ownership disclosed
Area code
341
In service
United States · since 2019

Oakland (overlay)

Area code 341 is an all-services overlay of area code 510, serving the same East Bay territory in Alameda and Contra Costa Counties. It became available for assignment in 2019.

The essentials Numbering data · NumberResearch · as of 2026-09-18
Place
Oakland (overlay)
Type
geographic
Status
in service
In service since
2019
Projected exhaust
2073 Q4

Status, dates and counts are read from NumberResearch (NANPA / CNAC / FCC records). Assignment records show initial assignees, not the carrier serving a number today.

A · Where it is

Where 341 is

Same as 510: western Alameda County and western Contra Costa County (East Bay)..

Communities served wholly or partly by 341:

OaklandBerkeleyFremontHaywardRichmondSan LeandroAlameda

Shares the 510 service area.

B · Relationships

How it relates to other codes

The codes 341 was split from, spawned, or shares its area with. A split divides the map and changes some numbers; an overlay shares the same ground and changes none — what's the difference?

Overlay · 2019 510 Oakland All-services overlay of the 510 numbering plan area.
What's changing. Active overlay of 510; ten-digit dialing required.
C · History

How 341 got here

2018-06-21
CPUC approved the 341 overlay relief plan for the 510 area.
Source: Wikipedia
2019-06-22
Ten-digit dialing became mandatory in the 510/341 area.
Source: Wikipedia
2019-07-22
New central office codes in 341 became available for assignment.
Source: Wikipedia
D · Capacity

How full it is

Prefixes assigned
127
Prefixes available
673
Thousands-blocks assigned
1,065

Prefix-assignment counts describe allocation to carriers, not how many individual numbers are in use. Full technical records: NumberResearch ↗.

Compare 341 with another code →
Sources
Wikipedia ↗
Area codes 510 and 341
NumberResearch.org ↗
Live status, dates, assignment counts and exhaust forecast — data as of 2026-09-18 (CC BY 4.0).

Place, relationships and history above are compiled by North American Numbers from the sources listed and last checked 2026-09-18. A check date is not an expert review — see how this is made. Flag an error.