Area Code 815 at a Glance
| Area code | 815 |
| Region | Illinois |
| Country | United States |
| Primary timezone | America/Chicago |
| Dialing format | +1 (815) NXX-XXXX |
Cities and Places Using Area Code 815
Based on prefix-level carrier data, area code 815 covers places including:
- Rockford, IL
- Crystal Lake, IL
- Plainfield, IL
- Joliet, IL
- McHenry, IL
- DeKalb, IL
- Woodstock, IL
- Freeport, IL
- Lockport, IL
- Sterling, IL
- Ottawa, IL
- Peru, IL
Frequently Asked Questions
Where is area code 815?
Area code 815 serves Illinois, United States.
Who is calling me from area code 815?
A call from area code 815 most likely originates from Illinois, but caller ID can be spoofed. If an unknown caller asks for personal or payment information, hang up and call the organization back on its official number.
How do I dial a 815 number?
Within North America: dial 1-815 followed by the 7-digit number. From abroad: your international prefix (like 00 or +), then 1 815 and the number.