505
Area code
Statusin service
Introduced1947-01-01
JurisdictionNM, US
Local dialing10D
Time zoneMountain
Last verified2026-09-17
Utilization 88.5% of assignable prefixes assigned
As of 09/17/2026
0%701 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 2001-03-16, most recent 2026-07-22.
Area codes serve rate-center geographies, not municipal boundaries. “NM” identifies the jurisdiction, not an exact city footprint.
Top assignees
Ranked by assigned prefixes · initial assignee ≠ current carrier| Rank | Assignee | Prefixes | Share |
|---|---|---|---|
| 01 | QWEST CORPORATION | 184 | 26.2% |
| 02 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - NM | 98 | 14% |
| 03 | NEW CINGULAR WIRELESS PCS, LLC | 77 | 11% |
| 04 | T-MOBILE USA, INC. | 65 | 9.3% |
| 05 | ONVOY, LLC - NM | 54 | 7.7% |
| 06 | BANDWIDTH.COM CLEC, LLC - NM | 24 | 3.4% |
| 07 | METROPCS, INC. | 19 | 2.7% |
| 08 | LEVEL 3 COMMUNICATIONS, LLC - NM | 17 | 2.4% |
| 09 | LEVEL 3 TELECOM OF NEW MEXICO, LLC - NM | 14 | 2% |
| 10 | NAVAJO COMM CO INC NM DBA NAVAJO COMM CO NM | 13 | 1.9% |
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- 2006-12-21 NPA 505 Split, Creating NPA 575 (New Mexico) split
- 1947-01-01Area code 505 entered service.
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 |
| 2008-09-03 | PL-380 ↗ | Reminder to update networks with the new 575 NPA for the 505 NPA Split in New Mexico |
| 2006-12-21 | PL-358 ↗ | NPA 505 Split, Creating NPA 575 (New Mexico) |
| 2002-11-25 | PL-328 ↗ | 505 NPA; Petition for Approval of Relief Plan Dismissed - New Mexico |
| 2002-01-11 | PL-312 ↗ | 505 NPA Split Suspended (New Mexico) |
| 2001-08-06 | PL-292 ↗ | 505 NPA Split, Creating 575 NPA (New Mexico) |