861
Area code
IL
United States geographic area code, in service since 2023-02-24. Part of the 309/861 overlay complex — ten-digit dialing required.
Statusin service
Introduced2023-02-24
JurisdictionIL, US
Local dialing10D
Time zoneCentral
Last verified2026-09-17
Utilization 2.5% of assignable prefixes assigned
As of 09/17/2026
0%20 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 2026-09-09, most recent 2026-09-15.
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 | MULTIPLE OCN LISTING | 9 | 45% |
| 02 | 5 | 25% | |
| 03 | EXIANT COMMUNICATIONS LLC | 2 | 10% |
| 04 | OPENTACT INC. | 1 | 5% |
| 05 | INTRADO COMMUNICATIONS, LLC | 1 | 5% |
| 06 | AHOI LLC | 1 | 5% |
| 07 | 8X8, INC. | 1 | 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- 2022-01-10 NPA 861 to Overlay NPA 309 (Illinois)
- 2023-02-24Area code 861 entered service (created from 309).
Planning letters & orders
Primary documents| Date | Document | Subject |
|---|---|---|
| 2022-01-10 | PL-577 ↗ | NPA 861 to Overlay NPA 309 (Illinois) |