861 area code
Where the 861 area code is, its overlay and how to dial a +1 861 number from anywhere.
The 861 area code is in Illinois, United States (Central (CT)). To call from abroad: +1 861 555-0123. It is an overlay, so all 10 digits are dialled.
The 861 area code is a geographic North American Numbering Plan (NANP) code covering Illinois. It has been in service since 19-Nov-2021 and sits in the Central (CT) time zone.
How to dial a 861 number
+1 861 555-01231 861 555-0123861 555-0123Other Illinois area codes
Frequently asked questions
Where is the 861 area code?
The 861 area code is in Illinois, United States (Central (CT)).
Is 861 an overlay area code?
Yes. 861 overlays the same region as 309, so callers dial all 10 digits.
Do I have to dial 10 digits for 861?
Yes — dial the area code plus the seven-digit number.
How do I call a 861 number from another country?
Dial your exit code (or +), then 1, then 861, then the number: +1 861 555-0123.
Source: NANPA numbering plan. An area code covers a region, not a precise address — a 861 number does not pinpoint a street or ZIP code.
Number holders in area code 861
Each prefix (the three digits after the area code) is assigned by NANPA to one telephone company. 19 prefixes are in use in 861, shared by 6 companies. The largest holders:
| Company | Prefixes | Share |
|---|---|---|
| Multiple Ocn Listing | 9 | 47% |
| 5 | 26% | |
| Exiant Communications LLC | 2 | 11% |
| Opentact Inc. | 1 | 5% |
| Intrado Communications, LLC | 1 | 5% |
| Ahoi LLC | 1 | 5% |
Source: NANPA central office code assignments. A number keeps its original prefix when it is ported to another carrier.
All US area codes United States +1 Map of area code 861 — cities & rate centres