Area Code 251
Alabama
Area code 251 serves Alabama, primarily Mobile, in the Central Time (CT) time zone. It was created from a split of area code 334.
Split Area Code
This area code was created by splitting an existing area code into separate geographic regions. When a split occurs, some customers in the original area code region are assigned the new area code.
This area code was split from area code 334 (Montgomery).
In service since: 18-Jun-2001
Historical Timeline of Area Code 251
Area code 251 was activated on June 18, 2001, as the 300th area code in the North American Numbering Plan. Created via a geographic split from area code 334, it relieved prefix exhaustion in southwestern Alabama where only 155 of 800 central office codes remained by April 2000. Source: Wikipedia
Key milestones:
- 1947: Alabama assigned its original area code 205 as part of the initial North American Numbering Plan
- 1995: Area code 334 created via split from 205, covering southern Alabama including Mobile
- 2000: By April, only 155 of 800 prefixes remained in 334. The Alabama PSC unanimously approved the 334/251 split on October 3 (Verizon Communications)
- 2001: NANPA issued PL-254 on January 2. Area code 251 activated June 18 with a six-month permissive dialing period (NANPA)
- 2002: Mandatory 251 dialing began January 7. Existing 334 numbers in the region were grandfathered
- 2021: Mandatory 10-digit dialing took effect October 24, required by FCC Order FCC 20-100 to support the 988 Suicide & Crisis Lifeline (Alabama PSC)
Area code 251 was the last area code in Alabama to transition from 7-digit to 10-digit local dialing. It serves the Mobile metropolitan area and surrounding counties in southwestern Alabama.
Unique Facts About Area Code 251
Area code 251 is the 300th area code in the North American Numbering Plan, was the last 7-digit dialing code in Alabama, and has operated without overlays since its creation in 2001. Source: Wikipedia
- 300th NANP area code: Area code 251 was the 300th area code activated in the North American Numbering Plan when it launched on June 18, 2001
- Last 7-digit dialing code in Alabama: Prior to October 2021, area code 251 was the only area code in Alabama still using 7-digit local dialing. The neighboring codes 205/659 and 256/938 already had overlays requiring 10-digit dialing, and 334 never had 988 assigned as a central office code (Alabama PSC Fact Sheet)
- Exhaust projection Q4 2033 (Wikipedia): NANPA projections as of October 2025 indicate area code 251 will exhaust available numbers by Q4 2033, driven by continued growth in the Mobile metro area
- Single-code territory: Area code 251 has operated without any overlays since its creation in 2001. Its parent code 334 received overlay 483 in February 2026
- Unanimous approval: When the Alabama PSC approved the 334/251 split in October 2000, the vote was unanimous 3-0, driven by only 155 of 800 central office prefixes remaining in 334
Area code 251 covers nine counties in southwestern Alabama, including Baldwin, Clarke, Escambia, Mobile, Monroe, and Washington. It operates in the Central Time Zone.
FCC Regulatory History
FCC Order FCC 20-100 (2020) required area code 251 to transition to mandatory 10-digit dialing by October 2021 because the 988 central office code was already assigned in the 251 area, conflicting with the new 988 Suicide & Crisis Lifeline. The code's regulatory history also includes the Alabama PSC's original 2000 approval of the 334/251 geographic split. Source: Alabama PSC
| Year | Event | Docket | Regulatory Action & Impact |
|---|---|---|---|
| 2000 | 334/251 Split Approval | Alabama PSC | Alabama PSC unanimously approved (3-0) the geographic split of 334 to create 251 covering southwestern Alabama, after finding only 155 of 800 central office prefixes remained (Verizon Communications) |
| 2001 | NANPA Planning Letter | PL-254 | NANPA formally notified the industry of the 334/251 split with a June 18, 2001 implementation date and six-month permissive dialing period (NANPA) |
| 2020 | FCC 988 Lifeline Order | FCC 20-100 | FCC approved 988 as the 3-digit abbreviated dialing code for the National Suicide Prevention Lifeline. Area code 251 was required to transition to mandatory 10-digit dialing because 988 was already assigned as a central office code in the 251 area (Alabama PSC Fact Sheet) |
| 2021 | Mandatory 10-Digit Dialing | Alabama PSC | Alabama PSC announced mandatory 10-digit dialing for area code 251 beginning October 24, 2021, with permissive dialing from April 24, 2021. Area code 334 was not affected because 988 was unassigned there (Alabama PSC Press Release) |
Demographics & Economics
- Total Population
- 864,231
- Population Density
- 63 people/sq mibelow U.S. average (U.S.: 94 people/sq mi)
- Median Household Income
- $58,119below U.S. median (U.S.: $78,538)
- Poverty Rate
- 16.1%above U.S. average (U.S.: 12.4%)
- Unemployment Rate
- 5.6%near U.S. average (U.S.: 5.2%)
- Education Attainment
- Bachelor's Degree+24.7%below U.S. average (U.S.: 35.0%)High School or Lower37.0%
Statistics are population-weighted aggregations from Census ACS 5-year estimates.See Sources for details.
Geographic Coverage
State
AL
Major Cities
- Mobile
- Daphne
- Fairhope
- Foley
- Prichard
- Tillmans Corner
- Saraland
- Gulf Shores
- Spanish Fort
- Atmore
- Orange Beach
- Bay Minette
- Robertsdale
- Satsuma
- Chickasaw
- Monroeville
- Semmes
- Brewton
- Theodore
- Jackson
- Loxley
- Citronelle
- Grand Bay
- Evergreen
and 59 more cities
Time Zone
- Central Time (CT)
Current Time
County Coverage
Population-weighted county share based on aggregated ZCTA population (100% = total mapped population for area code 251).
| County | Population | Share |
|---|---|---|
| Mobile, AL | 413,829 | 47.9% |
| Baldwin, AL | 255,936 | 29.6% |
| Conecuh, AL | 53,827 | 6.2% |
| Escambia, AL | 47,386 | 5.5% |
| Monroe, AL | 45,564 | 5.3% |
| Washington, AL | 24,127 | 2.8% |
| Clarke, AL | 14,726 | 1.7% |
| Choctaw, AL | 8,000 | 0.9% |
| Wilcox, AL | 836 | 0.1% |
Call Context
This area code spans a mix of urban centers and rural communities across AL, with Mobile as a primary city.
Nearby Area Codes
Area codes geographically closest to 251.
Other Area Codes in Alabama
Area codes that also serve Alabama, linked for easy comparison.
Frequently Asked Questions
Common questions about area code 251 and how phone numbering works.
251 was the first (and so far only) area code split from 334. 334 itself was split from 205 in 1995.
NANPA projections as of October 2025 indicate exhaust in Q4 2033, up from earlier Q4 2040 forecast.
Phone numbers assigned to area code 251 are tied to where they were originally provisioned — not the caller's current location. This code serving roughly 864k people covers Mobile in AL, so a number originally set up there will retain the 251 prefix even if the owner moves or uses VoIP. Mobile phones keep their original number when users relocate, and businesses often adopt local area codes to establish a regional presence.
Start by looking up the area code on this site to understand its geographic context — area code 251 is associated with Mobile in AL. For caller-specific details, use your carrier's caller ID features or check public directories. If you suspect fraud, you can report it to the FTC. To file a complaint about robocalls or spoofed numbers, visit the FCC Consumer Complaint Center. You can also register with the National Do Not Call Registry.
Area codes are sometimes "split" when an existing code runs out of available number combinations. In a split, the original territory is divided geographically, with each portion receiving its own area code. This area code was split from area code 334. See our guide on splits and overlays for details.