Area code 331
Illinois, United States · 224 prefixes · 24 exchanges · 25 carriers
Largest exchanges
- Aurora45
- Naperville33
- Downersgrv21
- St Charles18
- Lombard13
- Elmhurst10
- Lemont10
- Bartlett8
- Wheaton8
- W Chicago8
Largest carriers
- T-mobile Usa, Inc.42
- Onvoy, LLC39
- Cellco Partnership dba Verizon Wireless - Il33
- New Cingular Wireless Pcs, LLC - Il26
- Fractel, LLC18
- Bandwidth.com Clec, LLC - Il11
- Ton80 Communications, LLC9
- Level 3 Communications, LLC - Il6
- Peerless Network Of Illinois, LLC - Il5
- Onvoy Spectrum, LLC5
Most reported 331 numbers
No visitor reports yet in this area code.
FCC complaints
- 331-202-32041 · 2026-10-06
- 331-210-99061 · 2026-10-02
All 331 prefixes by exchange
Aurora · 45
331-203331-205331-206331-208331-212331-219331-220331-230331-250331-255331-256331-257331-258331-262331-269331-270331-274331-278331-287331-290331-293331-295331-300331-301331-302331-312331-319331-321331-329331-331331-336331-338331-339331-385331-425331-431331-452331-454331-575331-643331-666331-684331-707331-758331-980