959
Area code

CT

United States geographic area code, in service since 2014-08-30. Part of the 860/959 overlay complex — ten-digit dialing required.

Split from 860. Overlaid with 860 .

Statusin service
Introduced2014-08-30
JurisdictionCT, US
Local dialing10D
Time zoneEastern
Last verified2026-09-17
Utilization 22.3% of assignable prefixes assigned As of 09/17/2026
0%177 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 2014-09-18, most recent 2026-09-15.

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

Top assignees

Ranked by assigned prefixes · initial assignee ≠ current carrier
Largest initial assignees in area code 959
RankAssigneePrefixesShare
01 ONVOY, LLC - CT 46 26%
02 TON80 COMMUNICATIONS, LLC 27 15.3%
03 OMNIPOINT COMMUNICATIONS, INC. - CT 14 7.9%
04 CELLCO PARTNERSHIP DBA VERIZON WIRELESS - CT 14 7.9%
05 ONVOY SPECTRUM, LLC 9 5.1%
06 MULTIPLE OCN LISTING 9 5.1%
07 FRACTEL, LLC 8 4.5%
08 TELEPORT COMMUNICATIONS AMERICA, LLC - CT 6 3.4%
09 BANDWIDTH.COM CLEC, LLC - CT 5 2.8%
10 5 2.8%

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

Planning letters & orders

Primary documents
NANPA planning letters for area code 959
DateDocumentSubject
2013-08-27 PL-456 ↗ NPA 959 to Overlay NPA 860 (Connecticut)
2001-01-03 PL-255 ↗ Update on the Introduction of NPAs 475 and 959 (Connecticut)
2000-02-24 PL-217 ↗ NPA 475 To Overlay NPA 203; NPA 959 To Overlay NPA 860 (Connecticut)

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