Area Code Detail

Area Code 331

Illinois (Aurora, Naperville, Oswego; western suburbs of Chicago) · In service since October 7, 2007

IL
Reports, 30 Days 826

Recent FCC and FTC complaint records tied to this area code.

Reports, 180 Days 1,831

Broader complaint volume used to prioritize indexable pages.

Active Prefixes 238

Distinct NPA-NXX prefixes surfaced from routing and assignment data.

Carriers / Assignees 35

Named carriers, assignees, or code holders found in routing data.

Cities / Rate Centers 24

Distinct cities or rate centers attached to this area code.

States / Territories 1

Coverage footprint visible from NANPA, pooled block, and Canada routing data.

North American Phone Intelligence

Search a phone number, area code, exchange, or short code

Paste raw digits, a formatted phone number, an area code, an NPA-NXX block, or a short code. US and Canada phone lookups route automatically, and international iMessage checks are available separately.

Phone LookupTop ComplaintsArea CodesNPA-NXXiMessage
Overview

What this area code covers

Illinois (Aurora, Naperville, Oswego; western suburbs of Chicago)

overlaid on 630

Common cities and rate centers

Aurora Bartlett Batavia Big Rock Downers Grove Elburn Elmhurst Geneva Glen Ellyn Hinsdale Itasca Kaneville Lemont Lombard Naperville Oswego Plano Roselle

Top carriers and assignees

  • ONVOY, LLC · 575 routing rows
  • T-MOBILE USA, INC. · 361 routing rows
  • NEW CINGULAR WIRELESS PCS, LLC - IL · 317 routing rows
  • CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL · 301 routing rows
  • BANDWIDTH.COM CLEC, LLC - IL · 175 routing rows
  • ONVOY SPECTRUM, LLC · 78 routing rows
  • PEERLESS NETWORK OF ILLINOIS, LLC - IL · 67 routing rows
  • COMCAST IP PHONE, LLC · 65 routing rows
  • LEVEL 3 COMMUNICATIONS, LLC - IL · 52 routing rows
  • FRACTEL, LLC · 52 routing rows
  • COMMIO, LLC · 48 routing rows
  • TELEPORT COMMUNICATIONS AMERICA, LLC - IL · 41 routing rows
NPA-NXX

Prefix directory inside area code 331

Each prefix below is collapsed to one primary locality row so you can scan the area code by prefix without the duplicated block-level assignment rows.

Prefix Primary Rate Center Primary City State
331-200-XXXX BARTLETT Bartlett IL
331-201-XXXX DOWNERSGRV Downers Grove IL
331-202-XXXX ELMHURST Elmhurst IL
331-203-XXXX AURORA Aurora IL
331-204-XXXX NAPERVILLE Naperville IL
331-205-XXXX AURORA Aurora IL
331-206-XXXX AURORA Aurora IL
331-207-XXXX YORKVILLE Yorkville IL
331-208-XXXX AURORA Aurora IL
331-209-XXXX ELMHURST Elmhurst IL
331-210-XXXX ST CHARLES Saint Charles IL
331-211-XXXX IL
331-212-XXXX AURORA Aurora IL
331-213-XXXX NAPERVILLE Naperville IL
331-214-XXXX DOWNERSGRV Downers Grove IL
331-215-XXXX NAPERVILLE Naperville IL
331-216-XXXX OSWEGO Oswego IL
331-217-XXXX LOMBARD Lombard IL
331-218-XXXX WHEATON Wheaton IL
331-219-XXXX AURORA Aurora IL
331-220-XXXX AURORA Aurora IL
331-221-XXXX ELMHURST Elmhurst IL
331-222-XXXX ST CHARLES Saint Charles IL
331-223-XXXX ST CHARLES Saint Charles IL
331-224-XXXX ITASCA Itasca IL
331-225-XXXX ELMHURST Elmhurst IL
331-226-XXXX NAPERVILLE Naperville IL
331-227-XXXX SUGARGROVE Sugar Grove IL
331-228-XXXX ST CHARLES Saint Charles IL
331-229-XXXX NAPERVILLE Naperville IL
331-230-XXXX AURORA Aurora IL
331-231-XXXX NAPERVILLE Naperville IL
331-232-XXXX W CHICAGO West Chicago IL
331-233-XXXX DOWNERSGRV Downers Grove IL
331-234-XXXX SUGARGROVE Sugar Grove IL
331-235-XXXX ST CHARLES Saint Charles IL
331-236-XXXX WHEATON Wheaton IL
331-237-XXXX NAPERVILLE Naperville IL
331-238-XXXX DOWNERSGRV Downers Grove IL
331-239-XXXX YORKVILLE Yorkville IL
331-240-XXXX W CHICAGO West Chicago IL
331-241-XXXX LOMBARD Lombard IL
331-242-XXXX LOMBARD Lombard IL
331-243-XXXX LOMBARD Lombard IL
331-244-XXXX NAPERVILLE Naperville IL
331-245-XXXX BARTLETT Bartlett IL
331-246-XXXX LEMONT Lemont IL
331-247-XXXX NAPERVILLE Naperville IL
331-248-XXXX GENEVA Geneva IL
331-249-XXXX NAPERVILLE Naperville IL
331-250-XXXX AURORA Aurora IL
331-251-XXXX DOWNERSGRV Downers Grove IL
331-252-XXXX WARRENVL Warrenville IL
331-253-XXXX LEMONT Lemont IL
331-254-XXXX SUGARGROVE Sugar Grove IL
331-255-XXXX AURORA Aurora IL
331-256-XXXX AURORA Aurora IL
331-257-XXXX AURORA Aurora IL
331-258-XXXX AURORA Aurora IL
331-259-XXXX SUGARGROVE Sugar Grove IL
331-260-XXXX DOWNERSGRV Downers Grove IL
331-261-XXXX LEMONT Lemont IL
331-262-XXXX AURORA Aurora IL
331-263-XXXX ITASCA Itasca IL
331-264-XXXX HINSDALE Hinsdale IL
331-265-XXXX GENEVA Geneva IL
331-266-XXXX ST CHARLES Saint Charles IL
331-267-XXXX LOMBARD Lombard IL
331-268-XXXX SUGARGROVE Sugar Grove IL
331-269-XXXX AURORA Aurora IL
331-270-XXXX AURORA Aurora IL
331-271-XXXX HINSDALE Hinsdale IL
331-272-XXXX ST CHARLES Saint Charles IL
331-273-XXXX LEMONT Lemont IL
331-274-XXXX AURORA Aurora IL
331-275-XXXX BARTLETT Bartlett IL
331-276-XXXX ST CHARLES Saint Charles IL
331-277-XXXX LOMBARD Lombard IL
331-278-XXXX AURORA Aurora IL
331-279-XXXX ELMHURST Elmhurst IL
331-280-XXXX DOWNERSGRV Downers Grove IL
331-281-XXXX NAPERVILLE Naperville IL
331-282-XXXX HINSDALE Hinsdale IL
331-283-XXXX GENEVA Geneva IL
331-284-XXXX BARTLETT Bartlett IL
331-285-XXXX NAPERVILLE Naperville IL
331-286-XXXX ST CHARLES Saint Charles IL
331-287-XXXX AURORA Aurora IL
331-288-XXXX ELBURN Elburn IL
331-289-XXXX HINSDALE Hinsdale IL
331-290-XXXX AURORA Aurora IL
331-291-XXXX DOWNERSGRV Downers Grove IL
331-292-XXXX DOWNERSGRV Downers Grove IL
331-293-XXXX AURORA Aurora IL
331-294-XXXX NAPERVILLE Naperville IL
331-295-XXXX AURORA Aurora IL
331-296-XXXX WHEATON Wheaton IL
331-297-XXXX BATAVIA Batavia IL
331-298-XXXX NAPERVILLE Naperville IL
331-299-XXXX HINSDALE Hinsdale IL
331-300-XXXX AURORA Aurora IL
331-301-XXXX AURORA Aurora IL
331-302-XXXX AURORA Aurora IL
331-303-XXXX ELBURN Elburn IL
331-304-XXXX BARTLETT Bartlett IL
331-305-XXXX NAPERVILLE Naperville IL
331-306-XXXX DOWNERSGRV Downers Grove IL
331-307-XXXX LOMBARD Lombard IL
331-308-XXXX BARTLETT Bartlett IL
331-309-XXXX LEMONT Lemont IL
331-310-XXXX BIG ROCK Big Rock IL
331-311-XXXX IL
331-312-XXXX AURORA Aurora IL
331-313-XXXX NAPERVILLE Naperville IL
331-314-XXXX ST CHARLES Saint Charles IL
331-315-XXXX LOMBARD Lombard IL
331-316-XXXX NAPERVILLE Naperville IL
331-317-XXXX HINSDALE Hinsdale IL
331-318-XXXX LEMONT Lemont IL
331-319-XXXX AURORA Aurora IL
331-320-XXXX BARTLETT Bartlett IL
331-321-XXXX AURORA Aurora IL
331-322-XXXX LOMBARD Lombard IL
331-323-XXXX GLEN ELLYN Glen Ellyn IL
331-324-XXXX YORKVILLE Yorkville IL
331-325-XXXX LEMONT Lemont IL
331-326-XXXX DOWNERSGRV Downers Grove IL
331-327-XXXX ST CHARLES Saint Charles IL
331-328-XXXX NAPERVILLE Naperville IL
331-329-XXXX AURORA Aurora IL
331-330-XXXX NAPERVILLE Naperville IL
331-331-XXXX AURORA Aurora IL
331-332-XXXX NAPERVILLE Naperville IL
331-333-XXXX NAPERVILLE Naperville IL
331-334-XXXX BATAVIA Batavia IL
331-335-XXXX ST CHARLES Saint Charles IL
331-336-XXXX AURORA Aurora IL
331-337-XXXX OSWEGO Oswego IL
331-338-XXXX AURORA Aurora IL
331-339-XXXX AURORA Aurora IL
331-340-XXXX ITASCA Itasca IL
331-341-XXXX PLANO Plano IL
331-342-XXXX NAPERVILLE Naperville IL
331-343-XXXX DOWNERSGRV Downers Grove IL
331-344-XXXX W CHICAGO West Chicago IL
331-345-XXXX NAPERVILLE Naperville IL
331-346-XXXX NAPERVILLE Naperville IL
331-347-XXXX WHEATON Wheaton IL
331-348-XXXX ELBURN Elburn IL
331-356-XXXX BARTLETT Bartlett IL
331-373-XXXX OSWEGO Oswego IL
331-385-XXXX AURORA Aurora IL
331-388-XXXX SUGARGROVE Sugar Grove IL
331-399-XXXX DOWNERSGRV Downers Grove IL
331-400-XXXX OSWEGO Oswego IL
331-401-XXXX NAPERVILLE Naperville IL
331-411-XXXX IL
331-422-XXXX ST CHARLES Saint Charles IL
331-425-XXXX AURORA Aurora IL
331-426-XXXX LEMONT Lemont IL
331-431-XXXX AURORA Aurora IL
331-442-XXXX ST CHARLES Saint Charles IL
331-444-XXXX NAPERVILLE Naperville IL
331-452-XXXX AURORA Aurora IL
331-454-XXXX AURORA Aurora IL
331-456-XXXX ROSELLE Roselle IL
331-457-XXXX NAPERVILLE Naperville IL
331-462-XXXX LOMBARD Lombard IL
331-465-XXXX W CHICAGO West Chicago IL
331-466-XXXX GLEN ELLYN Glen Ellyn IL
331-472-XXXX NAPERVILLE Naperville IL
331-481-XXXX DOWNERSGRV Downers Grove IL
331-500-XXXX GENEVA Geneva IL
331-511-XXXX IL
331-529-XXXX NAPERVILLE Naperville IL
331-551-XXXX LOMBARD Lombard IL
331-555-XXXX IL
331-575-XXXX AURORA Aurora IL
331-588-XXXX ST CHARLES Saint Charles IL
331-591-XXXX IL
331-600-XXXX WHEATON Wheaton IL
331-611-XXXX IL
331-625-XXXX DOWNERSGRV Downers Grove IL
331-627-XXXX LOMBARD Lombard IL
331-631-XXXX DOWNERSGRV Downers Grove IL
331-642-XXXX ELMHURST Elmhurst IL
331-643-XXXX AURORA Aurora IL
331-645-XXXX ELMHURST Elmhurst IL
331-666-XXXX AURORA Aurora IL
331-684-XXXX AURORA Aurora IL
331-688-XXXX NAPERVILLE Naperville IL
331-700-XXXX IL
331-701-XXXX NAPERVILLE Naperville IL
331-702-XXXX NAPERVILLE Naperville IL
331-703-XXXX W CHICAGO West Chicago IL
331-704-XXXX KANEVILLE Kaneville IL
331-707-XXXX AURORA Aurora IL
331-711-XXXX IL
331-716-XXXX WHEATON Wheaton IL
331-717-XXXX OSWEGO Oswego IL
331-725-XXXX OSWEGO Oswego IL
331-732-XXXX GENEVA Geneva IL
331-746-XXXX KANEVILLE Kaneville IL
331-757-XXXX LEMONT Lemont IL
331-758-XXXX AURORA Aurora IL
331-771-XXXX ST CHARLES Saint Charles IL
331-775-XXXX DOWNERSGRV Downers Grove IL
331-777-XXXX DOWNERSGRV Downers Grove IL
331-788-XXXX GENEVA Geneva IL
331-800-XXXX W CHICAGO West Chicago IL
331-801-XXXX DOWNERSGRV Downers Grove IL
331-803-XXXX LEMONT Lemont IL
331-806-XXXX WHEATON Wheaton IL
331-808-XXXX PLANO Plano IL
331-811-XXXX IL
331-814-XXXX NAPERVILLE Naperville IL
331-825-XXXX GENEVA Geneva IL
331-826-XXXX ELMHURST Elmhurst IL
331-837-XXXX W CHICAGO West Chicago IL
331-850-XXXX BIG ROCK Big Rock IL
331-866-XXXX WHEATON Wheaton IL
331-867-XXXX YORKVILLE Yorkville IL
331-871-XXXX W CHICAGO West Chicago IL
331-888-XXXX WARRENVL Warrenville IL
331-899-XXXX LOMBARD Lombard IL
331-900-XXXX ELMHURST Elmhurst IL
331-901-XXXX ST CHARLES Saint Charles IL
331-903-XXXX DOWNERSGRV Downers Grove IL
331-911-XXXX IL
331-946-XXXX GLEN ELLYN Glen Ellyn IL
331-950-XXXX IL
331-958-XXXX IL
331-959-XXXX IL
331-976-XXXX IL
331-979-XXXX ELMHURST Elmhurst IL
331-980-XXXX AURORA Aurora IL
331-998-XXXX DOWNERSGRV Downers Grove IL
331-999-XXXX OSWEGO Oswego IL
Recent Signals

Latest complaint activity tied to 331

Complaint pages are the strongest indexing opportunity for this site right now, especially for exact phone numbers and toll-free exchanges.

FTC report from Dousman, WISCONSIN

August 13, 2026 at 11:29 PM

331-255-1975 was logged as a robocall. Category: Dropped call or no message. Violation date: August 8, 2026 at 8:10 PM.

FTC report from Chicago, ILLINOIS

August 13, 2026 at 10:05 PM

331-318-1997 was logged as a robocall. Violation date: August 6, 2026 at 4:23 PM.

FTC report from Greer, SOUTH CAROLINA

August 13, 2026 at 8:10 PM

331-292-6656 was logged as a robocall. Category: No Subject Provided. Violation date: August 12, 2026 at 11:25 AM.

FTC report from Evans, COLORADO

August 13, 2026 at 8:05 PM

331-600-0467 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 13, 2026 at 5:53 PM.

FTC report from Mokena, ILLINOIS

August 13, 2026 at 5:42 PM

331-296-3149 was logged as a unwanted call. Category: No Subject Provided. Violation date: August 11, 2026 at 12:38 PM.

FTC report from Mokena, ILLINOIS

August 13, 2026 at 5:31 PM

331-283-8853 was logged as a unwanted call. Category: No Subject Provided. Violation date: August 12, 2026 at 10:26 AM.

FTC report from Falls Church, VIRGINIA

August 13, 2026 at 4:02 PM

331-339-5243 was logged as a live voice. Category: Calls pretending to be government, businesses, or family and friends. Violation date: August 6, 2026 at 12:00 PM.

FTC report from Lynn, MASSACHUSETTS

August 13, 2026 at 3:02 PM

331-356-7811 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 13, 2026 at 12:00 AM.

FTC report from Hinsdale, ILLINOIS

August 13, 2026 at 2:52 PM

331-268-4348 was logged as a live voice. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 13, 2026 at 1:50 PM.

FTC report from Lisle, ILLINOIS

August 13, 2026 at 2:31 PM

331-286-5336 was logged as a robocall. Violation date: August 13, 2026 at 1:27 AM.

FTC report from ILLINOIS

August 13, 2026 at 2:25 PM

331-286-5001 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 13, 2026 at 12:31 AM.

FTC report from Marshville, NORTH CAROLINA

August 13, 2026 at 1:33 PM

331-529-9733 was logged as a robocall. Category: Calls pretending to be government, businesses, or family and friends. Violation date: August 13, 2026 at 1:26 PM.

FTC report from Minneapolis, MINNESOTA

August 13, 2026 at 12:10 PM

331-283-8569 was logged as a robocall. Category: No Subject Provided. Violation date: August 13, 2026 at 9:53 AM.

FTC report from Edmore, MICHIGAN

August 13, 2026 at 12:09 PM

331-261-1802 was logged as a live voice. Category: No Subject Provided. Violation date: August 13, 2026 at 9:34 AM.

FTC report from ILLINOIS

August 13, 2026 at 11:19 AM

331-529-9361 was logged as a robocall. Violation date: August 13, 2026 at 8:55 PM.

FTC report from Hanover Park, ILLINOIS

August 13, 2026 at 10:38 AM

331-629-3522 was logged as a live voice. Category: Work from home & other ways to make money. Violation date: August 12, 2026 at 1:45 PM.

FTC report from Woodbridge, VIRGINIA

August 13, 2026 at 9:45 AM

331-356-7263 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 13, 2026 at 9:40 AM.

FTC report from Claremore, OKLAHOMA

August 13, 2026 at 8:30 AM

331-207-6735 was logged as a live voice. Category: Lotteries, prizes & sweepstakes. Violation date: January 20, 2026 at 12:00 PM.

FTC report from New York, NEW YORK

August 12, 2026 at 10:42 PM

331-373-3005 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: July 31, 2026 at 9:31 AM.

FTC report from Smyrna, TENNESSEE

August 12, 2026 at 10:18 PM

331-356-8735 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 10, 2026 at 10:34 AM.

FTC report from CALIFORNIA

August 12, 2026 at 9:52 PM

331-356-9240 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 6, 2026 at 12:00 PM.

FTC report from New Haven, CONNECTICUT

August 12, 2026 at 6:42 PM

331-283-8750 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 3, 2026 at 12:16 PM.

FTC report from NORTH CAROLINA

August 12, 2026 at 5:08 PM

331-294-8892 was logged as a live voice. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 12, 2026 at 4:44 PM.

FTC report from Woodbridge, VIRGINIA

August 12, 2026 at 4:13 PM

331-235-9979 was logged as a live voice. Violation date: August 12, 2026 at 12:00 PM.

FTC report from NEW JERSEY

August 12, 2026 at 3:16 PM

331-356-8092 was logged as a robocall. Violation date: August 12, 2026 at 12:00 AM.

FTC report from ILLINOIS

August 12, 2026 at 3:07 PM

331-342-3011 was logged as a robocall. Violation date: August 12, 2026 at 1:29 PM.

FTC report from ILLINOIS

August 12, 2026 at 3:05 PM

331-342-3003 was logged as a robocall. Violation date: August 11, 2026 at 3:06 PM.

FTC report from ILLINOIS

August 12, 2026 at 3:04 PM

331-342-3003 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 7, 2026 at 1:34 PM.

FTC report from ILLINOIS

August 12, 2026 at 3:03 PM

331-269-3399 was logged as a live voice. Violation date: August 12, 2026 at 2:00 PM.

FTC report from Darien, ILLINOIS

August 12, 2026 at 2:40 PM

331-292-5256 was logged as a live voice. Category: Home improvement & cleaning. Violation date: August 12, 2026 at 1:36 AM.

FTC report from Ortonville, MICHIGAN

August 12, 2026 at 2:21 PM

331-348-6332 was logged as a robocall. Category: Warranties & protection plans. Violation date: July 16, 2026 at 12:00 AM.

FTC report from ILLINOIS

August 12, 2026 at 2:10 PM

331-269-3453 was logged as a live voice. Category: No Subject Provided. Violation date: August 11, 2026 at 11:30 AM.

FTC report from ILLINOIS

August 12, 2026 at 2:07 PM

331-239-9208 was logged as a live voice. Violation date: August 12, 2026 at 12:00 AM.

FTC report from Arlington Heights, ILLINOIS

August 12, 2026 at 1:51 PM

331-214-9090 was logged as a live voice. Category: Calls pretending to be government, businesses, or family and friends. Violation date: August 12, 2026 at 12:46 PM.

FTC report from Naugatuck-new Haven, CONNECTICUT

August 12, 2026 at 12:03 PM

331-356-7459 was logged as a robocall. Violation date: August 11, 2026 at 12:56 PM.

FTC report from OREGON

August 12, 2026 at 11:25 AM

331-356-9054 was logged as a live voice. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 12, 2026 at 8:12 AM.

FTC report from FLORIDA

August 11, 2026 at 11:24 PM

331-356-7066 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 10, 2026 at 9:11 AM.

FTC report from Whippany, NEW YORK

August 11, 2026 at 8:11 PM

331-356-8712 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: August 11, 2026 at 10:43 AM.

FTC report from Bartlett, ILLINOIS

August 11, 2026 at 5:47 PM

331-900-4867 was logged as a robocall. Category: Calls pretending to be government, businesses, or family and friends. Violation date: August 11, 2026 at 4:44 PM.

FTC report from ILLINOIS

August 11, 2026 at 5:28 PM

331-202-2414 was logged as a robocall. Category: Dropped call or no message. Violation date: August 1, 2026 at 3:59 PM.