551
Area code
NJ
United States geographic area code, in service since 2001-12-29. Part of the 201/551 overlay complex — ten-digit dialing required.
Statusin service
Introduced2001-12-29
JurisdictionNJ, US
Local dialing10D
Time zoneEastern
Last verified2026-09-17
Utilization 39.8% of assignable prefixes assigned
As of 09/17/2026
0%315 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 2001-10-17, most recent 2026-09-03.
Area codes serve rate-center geographies, not municipal boundaries. “NJ” identifies the jurisdiction, not an exact city footprint.
Top assignees
Ranked by assigned prefixes · initial assignee ≠ current carrier| Rank | Assignee | Prefixes | Share |
|---|---|---|---|
| 01 | ONVOY, LLC - NJ | 70 | 22.2% |
| 02 | OMNIPOINT COMMUNICATIONS, INC. - NJ | 69 | 21.9% |
| 03 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NJ | 44 | 14% |
| 04 | NEW CINGULAR WIRELESS PCS, LLC - DC | 27 | 8.6% |
| 05 | FRACTEL, LLC | 16 | 5.1% |
| 06 | BANDWIDTH.COM CLEC, LLC - NJ | 15 | 4.8% |
| 07 | MULTIPLE OCN LISTING | 11 | 3.5% |
| 08 | TON80 COMMUNICATIONS, LLC | 10 | 3.2% |
| 09 | CABLEVISION LIGHTPATH, INC. - NJ | 9 | 2.9% |
| 10 | METROPCS, INC. | 5 | 1.6% |
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- 2001-05-08 NPA 551 To Overlay NPA 201; NPA 862 To Overlay NPA 973; and NPA 848 To Overlay NPA 732 (New Jersey)
- 2001-12-29Area code 551 entered service (created from 201).
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 2001-05-08 | PL-277 ↗ | NPA 551 To Overlay NPA 201; NPA 862 To Overlay NPA 973; and NPA 848 To Overlay NPA 732 (New Jersey) |