217
Area code
IL
United States geographic area code, in service since 1947-01-01. Part of the 217/447 overlay complex — ten-digit dialing required.
Statusin service
Introduced1947-01-01
JurisdictionIL, US
Local dialing10D
Time zoneCentral
Last verified2026-09-17
Utilization 101% of assignable prefixes assigned
As of 09/17/2026
0%800 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 2001-03-12, most recent 2024-12-13.
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| Rank | Assignee | Prefixes | Share |
|---|---|---|---|
| 01 | ILLINOIS BELL TEL CO | 129 | 16.1% |
| 02 | FRONTIER NORTH, INC. - IL | 114 | 14.2% |
| 03 | NEW CINGULAR WIRELESS PCS, LLC - IL | 72 | 9% |
| 04 | LEVEL 3 COMMUNICATIONS, LLC - IL | 59 | 7.4% |
| 05 | CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL | 51 | 6.4% |
| 06 | ILLINOIS CONSOLIDATED TEL. CO. | 45 | 5.6% |
| 07 | T-MOBILE USA, INC. | 40 | 5% |
| 08 | FRONTIER COMMUNICATIONS OF THE CAROLINAS, INC - IL | 36 | 4.5% |
| 09 | CITIZENS TELECOM CO ILLINOIS-FRONTIER CITIZENS -IL | 26 | 3.3% |
| 10 | MEDIACOM TELEPHONY OF ILLINOIS, LLC - IL | 24 | 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- 2019-10-28 NPA 447 to Overlay NPA 217 (Illinois)
- 1947-01-01Area code 217 entered service.
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 2019-10-28 | PL-532 ↗ | NPA 447 to Overlay NPA 217 (Illinois) |