815 area code
Area code 815 is in Illinois. It covers Joliet, Rockford, Plainfield and 312 other places: 273 ZIP codes in Will, Winnebago, McHenry and 21 other counties. Local time there is , Central Time. In service since 1947; 779 (2007) overlays it, so a number from there can have either code.
Who calls from a 815 number
NANPA records the carrier each block of 815 numbers is assigned to. Of the 7.4 million 815 numbers assigned, 39% are with cable, internet-calling, business and other carriers (Onvoy); 32% with local phone companies (AT&T and Frontier); 27% with mobile carriers (T-Mobile, Verizon Wireless and AT&T Mobility); 2% with paging companies.
That is who the numbers were assigned to: people keep their number when they change carrier, so any one number may have moved since.
| Carrier | Kind | Share |
|---|---|---|
| AT&T | Landline | 17% |
| Frontier | Landline | 10% |
| T-Mobile | Mobile | 10% |
| Onvoy | Cable, VoIP, other | 9% |
| Verizon Wireless | Mobile | 8% |
| AT&T Mobility | Mobile | 6% |
An area code says where a number was issued, not where the caller is: people keep their numbers when they move, and caller ID can be set to show any number, which the FCC calls spoofing. If a call you did not expect asks for money or personal details, the FCC advises hanging up and calling the company back on a number you look up yourself. Unwanted calls can be reported to the FTC at ReportFraud.ftc.gov.
Places in area code 815
The 191 places with a telephone rate centre of their own using 815, largest first. Each links to its ZIP codes.
Nearby places using 815
These places have no rate centre of their own in NANPA's records; the nearest one uses 815. Near an area-code boundary that can be wrong for part of a town.
- Romeoville
- Loves Park
- Machesney Park
- Crest Hill
- Shorewood
- Bourbonnais
- Bradley
- Channahon
- Peru
- Frankfort Square
- LaSalle
- Rock Falls
- Lake Holiday
- Candlewick Lake
- Cortland
- Ingalls Park
- Diamond
- Ridgewood
- Davis Junction
- Fairmont
- Rockdale
- Preston Heights
- Lake Summerset
- Hillcrest
- Crystal Lawns
- The Galena Territory
- Pembroke Township
- De Pue
- Depue
- Limestone
- Westlake Village
- Kingston
- North Utica
- Timberlane
- Sunnyland
- Essex
- Chana
- Lockport Heights
- Braceville
- Lake Carroll
- Bonnie Brae
- Willow Lake
- Apple Canyon Lake
- Dalzell
- Millington
- Lost Nation
- Aroma Park
- Sun River Terrace
- Hopkins Park
- Godley
- South Wilmington
- Naplate
- Lindenwood
- Mark
- Como
- Cherry
- Greenwood
- Bonfield
- Malden
- Custer Park
ZIP codes in area code 815
273 ZIP codes in 247 towns, by the town each is mailed to, largest first. Each links to its own page.
Where 815 numbers are issued
NANPA's rate centres with the most 815 prefixes (each prefix is 10,000 numbers), under NANPA's own abbreviated names.
| Rate centre | Place | Prefixes |
|---|---|---|
ROCKFORD | Rockford | 89 |
JOLIET | Joliet | 62 |
KANKAKEE | Kankakee | 33 |
WOODSTOCK | Woodstock | 28 |
DE KALB | Dekalb | 24 |
FREEPORT | Freeport | 18 |
Counties
The counties of its ZIP codes, most residents first, with how many of its ZIP codes each has.
- Will County (20)
- Winnebago County (28)
- McHenry County (14)
- Kankakee County (17)
- LaSalle County (25)
- DeKalb County (13)
- Whiteside County (9)
- Boone County (5)
- Ogle County (17)
- Stephenson County (14)
- Grundy County (8)
- Lee County (14)
- Livingston County (17)
- Bureau County (21)
- Iroquois County (19)
- Jo Daviess County (9)
- Kendall County (2)
- Carroll County (7)
- Putnam County (7)
- Kane County (1)
- McLean County (1)
- Ford County (3)
- Marshall County (1)
- Henry County (1)
Which code covers where you are now? What area code am I in? answers from your location.
Questions about area code 815
Where is area code 815?
Area code 815 is in Illinois. It covers Joliet, Rockford, Plainfield and 312 other places: 273 ZIP codes in Will, Winnebago, McHenry and 21 other counties.
What ZIP codes are in area code 815?
273 ZIP codes, by the town each is mailed to: Joliet (6, 60431 to 60436), Rockford (14, 61101 to 61126), Plainfield (3, 60544 to 60586), Romeoville (60446) and 243 more towns. The full list is on this page.
What time zone is area code 815 in?
Central time.
Is a 815 number a mobile or a landline?
It can be either. 27% of 815 numbers are assigned to mobile carriers and 32% to local phone companies (NANPA, 2026-10-10); the rest are with cable, internet-calling, business and paging carriers. A number keeps its area code when it moves to another carrier.
What area codes overlay 815?
779. They cover the same area as 815, so a new number there can be given any of them.
Does a 815 number mean the caller is in Illinois?
Not necessarily. An area code says where the number was first issued. People keep their numbers when they move or switch carriers, and calling software can show any number, so a 815 call can come from anywhere.
Other area codes in Illinois
- 217 Springfield
- 224 Elgin
- 309 Peoria
- 312 Chicago
- 331 Aurora
- 447 Springfield
- 464 Orland Park
- 618 Belleville
- 630 Aurora
- 708 Orland Park
- 730 Belleville
- 773 Chicago
- 779 Rockford
- 847 Elgin
- 861 Peoria
- 872 Chicago
All 17 Illinois area codes, by area, with the cities each covers
Source: NANPA NPA database, central office code and thousands-block assignments, 2026-10-10. Places are matched to NANPA's rate centres by name; see sources.
Cite this page
zipcodes.pro. “Area code 815.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/area-code/815
Underlying data is public domain or openly licensed — sources, vintages and licences.