331 area code: where it is and which numbers are reported
331 covers Aurora, Naperville and Elmhurst in Illinois. 413 numbers in it drew 810 complaints between Oct 2, 2025 and Oct 31, 2026.
About area code 331
Reported 331 numbers
Most reported first. A number links to its own page once it has complaints from two or more days.
The 25 most reported of 413 numbers.
When 331 numbers were reported
Complaints a month, last 13 months
| November 2025: 1 |
| December 2025: 3 |
| January 2026: 4 |
| February 2026: 3 |
| March 2026: 1 |
| April 2026: 1 |
| May 2026: 3 |
| June 2026: 4 |
| July 2026: 245 |
| August 2026: 152 |
| September 2026: 134 |
| October 2026: 259 |
Hour of day, as reported in complaints
| 12 am: 2 |
| 1 am: 5 |
| 2 am: 3 |
| 3 am: 4 |
| 4 am: 2 |
| 6 am: 20 |
| 7 am: 26 |
| 8 am: 29 |
| 9 am: 69 |
| 10 am: 81 |
| 11 am: 90 |
| 12 pm: 101 |
| 1 pm: 78 |
| 2 pm: 52 |
| 3 pm: 49 |
| 4 pm: 38 |
| 5 pm: 29 |
| 6 pm: 33 |
| 7 pm: 14 |
| 8 pm: 15 |
| 9 pm: 11 |
| 10 pm: 4 |
| 11 pm: 2 |
The most reported 331 prefixes
Complaints by the three digits after the area code.
- (331) 888
- 32140%
- (331) 248
- 678%
- (331) 356
- 253%
- (331) 296
- 152%
- (331) 297
- 142%
331 numbers that unwanted calls gave to contact
Numbers in this area code that complaints named as the number a call or text asked people to contact.
Towns and cities in area code 331
26 places its numbers are assigned to, the ones with the most numbers first.
- Aurora
- Naperville
- Elmhurst
- Bensenville
- Oak Brook
- Bolingbrook
- Wheaton
- St. Charles
- Downers Grove
- Lombard
- Glen Ellyn
- Geneva
- West Chicago
- Batavia
- Itasca
- Addison
- Lemont
- Warrenville
- Oswego
- Yorkville
- Elburn
- Sugar Grove
- Plano
- Big Rock
- Hinsdale
- Winfield
Check a number
Enter a number. Bewary checks it against FTC and FCC scam and robocall complaints and its scam lists.
Sources
Complaints consumers filed with the FCC and FTC, Oct 2, 2025 to Oct 31, 2026. Bewary counts the reports and does not check each one. Scammers can fake the number that shows on your phone, so a reported number may belong to someone who never called you.