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331 Area Code 🌍☎️

Area Code Profile · Illinois

The 331 area code is located in the state of Illinois and covers 61 cities, serving a total population of approximately 1,652,441. Major cities covered by the 331 area code include Aurora, Joliet, Naperville, Bolingbrook, Wheaton (which represents the most populated areas). There are a total of 211 telephone prefix exchanges in this area code, which support an estimated 2,110,000 active or assignable phone numbers. These prefix lines are operated by 27 distinct carriers, with Aurora as the primary rate center location.

Central Time61 Cities211 Prefixes

Reverse Phone Lookup in Aurora, Illinois

Unmask unknown callers, verify telemarketing reports, and view detailed owner information for any phone number beginning with area code (331).

How it works

1

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Provide any 10-digit phone number starting with the (331) area code.

2

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Our system scans public registries, carrier mappings, and spam reports.

3

Reveal Report

Access location details, line type, carrier, owner information, and safety levels.

Neighborhood Demographics

Calculated demographics and census summary estimations for area code 331.

33.8 y/oMedian Age
$58,800Median Income
$673,000Median Home Value
1,652,441Total Population

Telemarketer Complaints

Most recent complaints and comments for phone numbers beginning with 331.

Did you receive an unwanted call from a (331) phone number?

Help the community identify spammers by filing a comment.

(331) 741-6646May 19, 2026Debt Collector
Automated voice caller looking for someone named David. Keeps calling repeatedly asking to settle a debt. I have had this number for years and don't know David.
See Details
(331) 754-6663May 18, 2026Political
Pre-recorded campaign call promoting a local candidate. Did not respect my request to be placed on the Do Not Call list.
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(331) 767-6680May 17, 2026Scam / Fraud
Received a text and follow-up call saying my bank account was locked due to suspicious transactions. Included a link to a fake login portal. Do not click!
See Details
(331) 780-6697May 16, 2026Robocall
Robocall regarding health insurance plans. Said my current coverage was expiring and offered a "free consultation". Calling multiple times a day from slightly different numbers.
See Details

Cities in the 331 Area Code

The most populous cities in area code 331 are: Aurora (197,899), Joliet (147,433), Naperville (141,853), Bolingbrook (73,366), and Wheaton (52,894).

Other cities in the 331 area code include:

Downers Grove, Elmhurst, Lombard, Bartlett, Streamwood, Carol Stream, Romeoville, Plainfield, Hanover Park, Addison, Glendale Heights, St. Charles, Woodridge, Oswego, Glen Ellyn, West Chicago, Batavia, Westmont, Roselle, Lisle, Darien, Bloomingdale, Villa Park, Geneva, Montgomery.

CityPopulation% in Area Code
Aurora197,899100%
Joliet147,4336%
Naperville141,853100%
Bolingbrook73,36691%
Wheaton52,894100%
Downers Grove47,833100%
Elmhurst44,121100%
Lombard43,165100%
Bartlett41,20894%
Streamwood39,85897%
Carol Stream39,711100%
Romeoville39,6809%
Plainfield39,58120%
Hanover Park37,973100%
Addison36,942100%
Glendale Heights34,208100%
St. Charles32,974100%
Woodridge32,971100%
Oswego30,355100%
Glen Ellyn27,450100%

Showing top 20 of 61 cities.

What Time Zone is Area Code 331?

Central Time Zone

Abbreviation: CT · UTC Offset: UTC-6

The 331 area code lies within the Central Time Zone (CT, UTC-6).

Nearby Area Codes

217Springfield, Illinois224Elgin, Illinois309Peoria, Illinois312Chicago, Illinois447Springfield, Illinois464Cicero, Illinois618Belleville, Illinois630Aurora, Illinois708Cicero, Illinois730Belleville, Illinois

Phone Prefixes in the 331 Area Code

211 prefixes found · 27 carriers · 24 rate centers

PrefixCarrierRate Center
(331) 200T-MOBILE USA, INC.BARTLETT
(331) 201CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILDOWNERSGRV
(331) 202METROPCS, INC.ELMHURST
(331) 203T-MOBILE USA, INC.AURORA
(331) 204ONVOY, LLCNAPERVILLE
(331) 205T-MOBILE USA, INC.AURORA
(331) 206T-MOBILE USA, INC.AURORA
(331) 207LEVEL 3 COMMUNICATIONS, LLC - ILYORKVILLE
(331) 208T-MOBILE USA, INC.AURORA
(331) 209LEVEL 3 COMMUNICATIONS, LLC - ILELMHURST
(331) 210PEERLESS NETWORK OF ILLINOIS, LLC - ILST CHARLES
(331) 212MCIMETRO ACCESS TRANSMISSION SERVICES LLC - ILAURORA
(331) 213CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILNAPERVILLE
(331) 214CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILDOWNERSGRV
(331) 215CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILNAPERVILLE
(331) 216NEW CINGULAR WIRELESS PCS, LLC - ILOSWEGO
(331) 217ONVOY, LLCLOMBARD
(331) 218T-MOBILE USA, INC.WHEATON
(331) 219TELNYX LLCAURORA
(331) 220T-MOBILE USA, INC.AURORA
(331) 221ILLINOIS BELL TEL COELMHURST
(331) 222NEW CINGULAR WIRELESS PCS, LLC - ILST CHARLES
(331) 223NEW CINGULAR WIRELESS PCS, LLC - ILST CHARLES
(331) 224ONVOY, LLCITASCA
(331) 225METROPCS, INC.ELMHURST
(331) 226T-MOBILE USA, INC.NAPERVILLE
(331) 227CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILSUGARGROVE
(331) 228OVATION COMMUNICATIONS OF ILLINOIS, INC.ST CHARLES
(331) 229CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILNAPERVILLE
(331) 230T-MOBILE USA, INC.AURORA
(331) 231NEW CINGULAR WIRELESS PCS, LLC - ILNAPERVILLE
(331) 232NEW CINGULAR WIRELESS PCS, LLC - ILW CHICAGO
(331) 233TELNYX LLCDOWNERSGRV
(331) 234CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILSUGARGROVE
(331) 235NEW CINGULAR WIRELESS PCS, LLC - ILST CHARLES
(331) 236T-MOBILE USA, INC.WHEATON
(331) 237MCIMETRO ACCESS TRANSMISSION SERVICES LLC - ILNAPERVILLE
(331) 238TELEPORT COMMUNICATIONS AMERICA, LLC - ILDOWNERSGRV
(331) 239ONVOY, LLCYORKVILLE
(331) 240PEERLESS NETWORK OF ILLINOIS, LLC - ILW CHICAGO
(331) 241ONVOY, LLCLOMBARD
(331) 242T-MOBILE USA, INC.LOMBARD
(331) 243T-MOBILE USA, INC.LOMBARD
(331) 244ONVOY, LLCNAPERVILLE
(331) 245T-MOBILE USA, INC.BARTLETT
(331) 246T-MOBILE USA, INC.LEMONT
(331) 247VONAGE AMERICA LLCNAPERVILLE
(331) 248COMCAST IP PHONE, LLCGENEVA
(331) 249ONVOY, LLCNAPERVILLE
(331) 250T-MOBILE USA, INC.AURORA
(331) 251CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILDOWNERSGRV
(331) 252TELEPORT COMMUNICATIONS AMERICA, LLC - ILWARRENVL
(331) 253T-MOBILE USA, INC.LEMONT
(331) 254T-MOBILE USA, INC.SUGARGROVE
(331) 255ONVOY, LLCAURORA
(331) 256CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILAURORA
(331) 257NEW CINGULAR WIRELESS PCS, LLC - ILAURORA
(331) 258ONVOY, LLCAURORA
(331) 259PEERLESS NETWORK OF ILLINOIS, LLC - ILSUGARGROVE
(331) 260TELEPORT COMMUNICATIONS AMERICA, LLC - ILDOWNERSGRV
(331) 261T-MOBILE USA, INC.LEMONT
(331) 262T-MOBILE USA, INC.AURORA
(331) 263ONVOY, LLCITASCA
(331) 264LEVEL 3 COMMUNICATIONS, LLC - ILHINSDALE
(331) 265ONVOY, LLCGENEVA
(331) 266NEW CINGULAR WIRELESS PCS, LLC - ILST CHARLES
(331) 267VONAGE AMERICA LLCLOMBARD
(331) 268T-MOBILE USA, INC.SUGARGROVE
(331) 269T-MOBILE USA, INC.AURORA
(331) 270ONVOY, LLCAURORA
(331) 271ONVOY, LLCHINSDALE
(331) 272ONVOY, LLCST CHARLES
(331) 273ONVOY, LLCLEMONT
(331) 274T-MOBILE USA, INC.AURORA
(331) 275T-MOBILE USA, INC.BARTLETT
(331) 276CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILST CHARLES
(331) 277NEW CINGULAR WIRELESS PCS, LLC - ILLOMBARD
(331) 278NEW CINGULAR WIRELESS PCS, LLC - ILAURORA
(331) 279PAETEC COMMUNICATIONS, INC. - ILELMHURST
(331) 280CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILDOWNERSGRV
(331) 281ILLINOIS BELL TEL CONAPERVILLE
(331) 282ONVOY, LLCHINSDALE
(331) 283T-MOBILE USA, INC.GENEVA
(331) 284T-MOBILE USA, INC.BARTLETT
(331) 285CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILNAPERVILLE
(331) 286CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILST CHARLES
(331) 287BANDWIDTH.COM CLEC, LLC - ILAURORA
(331) 288TON80 COMMUNICATIONS, LLCELBURN
(331) 289T-MOBILE USA, INC.HINSDALE
(331) 290CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILAURORA
(331) 291CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILDOWNERSGRV
(331) 292ONVOY SPECTRUM, LLCDOWNERSGRV
(331) 293NEW CINGULAR WIRELESS PCS, LLC - ILAURORA
(331) 294CELLCO PARTNERSHIP DBA VERIZON WIRELESS - ILNAPERVILLE
(331) 295NUSO, LLCAURORA
(331) 296DISH WIRELESS, LLCWHEATON
(331) 297ONVOY, LLCBATAVIA
(331) 298ONVOY, LLCNAPERVILLE
(331) 299FRACTEL, LLCHINSDALE
(331) 300T-MOBILE USA, INC.AURORA

Showing first 100 of 211 prefixes.

Frequently Asked Questions

Where is area code 331?
Area code 331 is located in Illinois, covering cities including Aurora, Joliet, Naperville.
What time zone is area code 331?
Area code 331 is in the Central Time Zone (CT, UTC-6).
What state is area code 331?
Area code 331 is in Illinois.