Area Code 331 — Illinois

Active General Purpose Code Overlay United States

Area code 331 is located in Illinois and operates on Central Time . The largest city served is Aurora .

Coverage Area

Area code 331 — Illinois

Area Code Details

Area Code: 331
State / Province: Illinois (IL)
Country: United States
Time Zone: Central Time Central Time
Local Time Now: —
Status: Active
Code Type: General Purpose Code
In Service Since: October 7, 2007
Assigned: July 23, 1999
Population Served: ~493,258 est.
Overlay Complex: 331/630

Cities Served

Largest City Aurora

Aurora Wheaton Downers Grove Elmhurst Bartlett Oswego West Chicago Geneva Bensenville

History & Relationships

Split from

Overlay complex — shares geography with

Rate Centers & Exchanges

9 rate centers identified within area code 331

View exchanges →

Other Area Codes in Illinois

Nearby Area Codes

Frequently Asked Questions About Area Code 331

What state is area code 331?

Area code 331 is located in Illinois, United States.

Where is area code 331 from?

Area code 331 originates from Illinois. It operates in the Central Time zone.

What time zone is area code 331?

Area code 331 falls within the Central Time zone (Central Time).

What cities are in area code 331?

Area code 331 serves cities including Aurora, Wheaton, Downers Grove, Elmhurst, Bartlett, Oswego, West Chicago, Geneva, and more.

Is a call from area code 331 a scam?

Area code 331 is a legitimate general purpose code area code serving Illinois. Like any area code, individual numbers using 331 can be used for scam calls — always verify the specific number if you receive an unexpected or suspicious call.