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US area code · Illinois

Area code 815

Where the 815 area code is, its overlay and how to dial a +1 815 number from anywhere.

CoversBelvidere, IllinoisTime zoneCentral (CT)TypeOverlay
Quick answer

The 815 area code is in Belvidere, Illinois, United States (Central (CT)). To call from abroad: +1 815 555-0123. It is an overlay, so all 10 digits are dialled.

StateIllinois
Main areaBelvidere
Time zoneCentral (CT)
TypeOverlay
10-digit dialingRequired
In service since01-Jan-1947

The 815 area code is a geographic North American Numbering Plan (NANP) code covering Belvidere, Illinois. It has been in service since 01-Jan-1947 and sits in the Central (CT) time zone.

Overlay 815 shares its region

Several area codes cover the same geographic area, so two neighbours can have different codes. Because of the overlay, you must dial all 10 digits (area code + number) even for local calls.

815779

How to dial a 815 number

From abroad+1 815 555-0123
Within the US / Canada1 815 555-0123
Locally (same area)815 555-0123

Cities in the 815 area code

A 815 number is usually in one of these places in Illinois — 8 counties.

Belvidere BooneCrystal Lake MchenryDeKalb DekalbFreeport StephensonJoliet WillKankakee KankakeeLoves Park WinnebagoMachesney Park WinnebagoMcHenry ";MchenryRockford WinnebagoRomeoville WillWoodstock Mchenry

Other Illinois area codes

217224309312331447464618630708730773779847861872

Frequently asked questions

Where is the 815 area code?

The 815 area code is in Belvidere, Illinois, United States (Central (CT)).

Is 815 an overlay area code?

Yes. 815 overlays the same region as 779, so callers dial all 10 digits.

Do I have to dial 10 digits for 815?

Yes — dial the area code plus the seven-digit number.

How do I call a 815 number from another country?

Dial your exit code (or +), then 1, then 815, then the number: +1 815 555-0123.

Source: NANPA numbering plan. An area code covers a region, not a precise address — a 815 number does not pinpoint a street or ZIP code.

Missed a call from +1 815?

In the 30 days to September 24, 2026, 933 unwanted calls showing a 815 number were reported to the US Federal Trade Commission, 61% of them recorded messages or robocalls. That puts 815 at #52 of 670 area codes reported.

Other364
Reducing your debt (credit cards, mortgage, student loans)256
Dropped call or no message69
Calls pretending to be government, businesses, or family and friends66
Before you call back
  • If you do not know anyone in Illinois, do not call back: a genuine caller will leave a message or send a text.
  • Scammers fake the number shown on caller ID, so a 815 number can hide a caller anywhere in the world.
  • Never give a code received by text or a bank detail to an unknown caller. In the US, calls can be reported at reportfraud.ftc.gov.

Who issues +1 815 numbers

Phone companies hold blocks of numbers in each area code. The main holders in 815:

Illinois Bell Tel Co 157Frontier North, Inc. 133Level 3 Communications, LLC 76Cellco Partnership Dba Verizon Wireless 50Aero North Communications, Inc. 43New Cingular Wireless PCS, LLC 42

About 16.5% of the 800 prefixes in use belong to mobile carriers: a 815 number is often a cell phone, and it may have moved to another carrier since.

Sources: FTC Do Not Call reported calls (numbers as reported by consumers, not verified), NANPA central office code assignments.

All US area codes United States +1 Map of area code 815 — cities & rate centres