534
Area code
WI
United States geographic area code, in service since 2010-08-14. Part of the 534/715 overlay complex — ten-digit dialing required.
Statusin service
Introduced2010-08-14
JurisdictionWI, US
Local dialing10D
Time zoneCentral
Last verified2026-09-17
Utilization 14.3% of assignable prefixes assigned
As of 09/17/2026
0%113 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 2011-12-07, most recent 2026-08-19.
Area codes serve rate-center geographies, not municipal boundaries. “WI” identifies the jurisdiction, not an exact city footprint.
Top assignees
Ranked by assigned prefixes · initial assignee ≠ current carrier| Rank | Assignee | Prefixes | Share |
|---|---|---|---|
| 01 | NEW CINGULAR WIRELESS PCS, LLC - IL | 19 | 16.8% |
| 02 | LEVEL 3 COMMUNICATIONS, LLC - WI | 18 | 15.9% |
| 03 | ONVOY, LLC - WI | 14 | 12.4% |
| 04 | FRACTEL, LLC | 14 | 12.4% |
| 05 | TON80 COMMUNICATIONS, LLC | 10 | 8.8% |
| 06 | MULTIPLE OCN LISTING | 10 | 8.8% |
| 07 | 5 | 4.4% | |
| 08 | BOOST SUBSCRIBERCO L.L.C. | 3 | 2.7% |
| 09 | ONVOY SPECTRUM, LLC | 2 | 1.8% |
| 10 | NUSO, LLC | 2 | 1.8% |
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- 2008-12-22 NPA 534 to Overlay NPA 715 (Wisconsin)
- 2010-08-14Area code 534 entered service (created from 715).
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 2008-12-22 | PL-384 ↗ | NPA 534 to Overlay NPA 715 (Wisconsin) |