US Area Code

815

Northern Illinois · Illinois

Area code 815 serves Rockford, Joliet, DeKalb and surrounding areas in Illinois. Look up any 815 number below to check for spam, see caller ID, carrier, and line type.

Area Code Details

State / Territory
Illinois
Region
Northern Illinois
Major Cities
Rockford, Joliet, DeKalb
Timezone
Central Time
Country
United States
Format
+1 (815) XXX-XXXX

Other Illinois area codes

217 Central Illinois224 Northern Illinois309 Central Illinois312 Chicago331 Chicago Suburbs447 East-Central Illinois464 South Cook County618 Southern Illinois630 DuPage County708 South/Southwest Suburbs730 Central Illinois773 Chicago779 Northern Illinois847 North Cook / Lake County872 Chicago