North American Numbers Source-cited · ownership disclosed
Area code
251
In service
United States · since 2001

Mobile

Serves southwestern Alabama including Mobile and the Gulf Coast. It was created on June 18, 2001, as a split from area code 334.

The essentials Numbering data · NumberResearch · as of 2026-09-18
Place
Mobile
Type
geographic
Status
in service
In service since
2001
Projected exhaust
2039 Q1

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 251 is

Southwestern Alabama; fully covers Mobile, Baldwin and Washington counties plus parts of six more..

Communities served wholly or partly by 251:

MobileDaphneFairhopeGulf ShoresOrange BeachFoleyBay MinetteAtmoreBrewtonMonroeville
B · Relationships

How it relates to other codes

The codes 251 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?

Split from · 2001 334 Montgomery 251 split off from 334 to serve the southwestern corner.
What's changing. No overlay; single area code for its region.
C · History

How 251 got here

2001-06-18
Created as a split from area code 334; permissive use of 334 continued through January 7, 2002.
Source: Wikipedia
2021-10
Transitioned to ten-digit dialing for the nationwide 988 designation.
Source: Wikipedia
D · Capacity

How full it is

Prefixes assigned
543
Prefixes available
257
Thousands-blocks assigned
2,982

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

Compare 251 with another code →
Sources
Wikipedia ↗
Area code 251
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.