Area code

IL

United States geographic area code, in service since 1996-01-20. Part of the 224/847 overlay complex — ten-digit dialing required.

Split from 708. Created 224. Overlaid with 224 .

Statusin service

Introduced1996-01-20

JurisdictionIL, US

Local dialing1+10D

Time zoneCentral

Last verified2026-09-17

Utilization 100.9% of assignable prefixes assigned As of 09/17/2026

0%799 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 2001-02-09, most recent 2026-03-17.

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

Top assignees

Ranked by assigned prefixes · initial assignee ≠ current carrier

Largest initial assignees in area code 847
Rank	Assignee	Prefixes	Share
01	ILLINOIS BELL TEL CO	361	45.2%
02	NEW CINGULAR WIRELESS PCS, LLC - IL	80	10%
03	TELEPORT COMMUNICATIONS AMERICA, LLC - IL	57	7.1%
04	T-MOBILE USA, INC.	54	6.8%
05	LEVEL 3 COMMUNICATIONS, LLC - IL	46	5.8%
06	MCIMETRO ACCESS TRANSMISSION SERVICES LLC	44	5.5%
07	CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL	39	4.9%
08	PAETEC ITEL, LLC	26	3.3%
09	MCIMETRO ACCESS TRANSMISSION SERVICES LLC - IL	23	2.9%
10	SPOK, INC.	18	2.3%

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

1999-02-23 No Mandatory date set for 1 +10 digit dialing in Chicago NPA 847/224 Overlay; update to PL-127 other
1997-10-10 Declaration of Jeopardy Situation in NPA 847 (Illinois) jeopardy
1996-01-20Area code 847 entered service (created from 708).

Planning letters & orders

Primary documents

NANPA planning letters for area code 847
Date	Document	Subject
2001-10-17	PL-305 ↗	Mandatory Dialing Date Established for NPAs 847 and 224 (Illinois)
1995-07-27	IL-95-07-015 ↗	NANP-SPLIT OF 708 (ILLINOIS) NUMBERING PLAN AREA (NPA)

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