435
Area code

UT

United States geographic area code, in service since 1997-09-21.

Split from 801.

Statusin service
Introduced1997-09-21
JurisdictionUT, US
Local dialing7D
Time zoneMountain
Last verified2026-09-17
Utilization 66.3% of assignable prefixes assigned As of 09/17/2026
0%525 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 2001-02-02, most recent 2026-09-15.

Area codes serve rate-center geographies, not municipal boundaries. “UT” identifies the jurisdiction, not an exact city footprint.

Top assignees

Ranked by assigned prefixes · initial assignee ≠ current carrier
Largest initial assignees in area code 435
RankAssigneePrefixesShare
01 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - UT 63 12%
02 QWEST CORPORATION 58 11%
03 NEW CINGULAR WIRELESS PCS, LLC 55 10.5%
04 ONVOY, LLC - UT 43 8.2%
05 T-MOBILE USA, INC. 41 7.8%
06 CITIZENS TELECOM-UTAH DBA FRONTIER COMM OF UT 28 5.3%
07 SOUTH CENTRAL UTAH TEL. ASSN., INC. 24 4.6%
08 LEVEL 3 COMMUNICATIONS, LLC - UT 23 4.4%
09 15 2.9%
10 UBTA-UBET COMMUNICATIONS, INC. DBA STRATA NETWORKS 13 2.5%

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
  • 1997-09-21Area code 435 entered service (created from 801).

Planning letters & orders

Primary documents
NANPA planning letters for area code 435
DateDocumentSubject
1998-06-12 PL-126 ↗ Extension of Permissive Dialing Period for Utah 801 and 435 NPA Relief; Reference PL-NANP-065
1997-05-30 PL-065 ↗ NANP- Split of 801 (Utah) Numbering Plan Area (NPA)

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