251
Area code
Statusin service
Introduced2001-06-18
JurisdictionAL, US
Local dialing10D
Time zoneCentral
Last verified2026-09-17
Utilization 68.4% of assignable prefixes assigned
As of 09/17/2026
0%542 of ~792 assignable NXX values (200–999 excl. N11)100%
Prefix-level assignment does not equal number-level exhaustion; thousands-block pooling extends capacity. First assignment on record 2001-01-03, most recent 2026-08-12.
Area codes serve rate-center geographies, not municipal boundaries. “AL” identifies the jurisdiction, not an exact city footprint.
Top assignees
Ranked by assigned prefixes · initial assignee ≠ current carrier| Rank | Assignee | Prefixes | Share |
|---|---|---|---|
| 01 | BELLSOUTH TELECOMM INC DBA SOUTH CENTRAL BELL TEL | 88 | 16.2% |
| 02 | NEW CINGULAR WIRELESS PCS, LLC - GA | 71 | 13.1% |
| 03 | ONVOY, LLC - AL | 66 | 12.2% |
| 04 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - AL | 38 | 7% |
| 05 | ELISKA WIRELESS VENTURES SUBSIDIARY I, LLC | 29 | 5.4% |
| 06 | BRIGHTSPEED OF SOUTHERN ALABAMA | 29 | 5.4% |
| 07 | PAETEC ITEL, LLC | 19 | 3.5% |
| 08 | ONVOY SPECTRUM, LLC | 17 | 3.1% |
| 09 | MCC TELEPHONY OF THE SOUTH, LLC - AL | 17 | 3.1% |
| 10 | LEVEL 3 COMMUNICATIONS, LLC - AL | 17 | 3.1% |
Important: these are initial assignees from NANPA CO-code records — the carrier a prefix was originally assigned to. Because of number portability, the current serving carrier of any individual number may differ.
Change history
Recorded events for this NPA- 2001-06-18Area code 251 entered service (created from 334).
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 2021-01-08 | PL-556 ↗ | Transition to 10-digit dialing (for 988 as 3-digit access to National Suicide Prevention Lifeline) – supersedes PL-544 |
| 2020-08-17 | PL-544 ↗ | Transition to 10-digit dialing (for 988 as 3-digit access to National Suicide Prevention Hotline |
| 2001-01-02 | PL-254 ↗ | 334 NPA Split, Creating 251 NPA (Alabama) |