Area Code Detail

Area Code 331

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

IL
Reports, 30 Days 101

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

Reports, 180 Days 1,113

Broader complaint volume used to prioritize indexable pages.

Active Prefixes 236

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

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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 · 562 routing rows
  • T-MOBILE USA, INC. · 363 routing rows
  • NEW CINGULAR WIRELESS PCS, LLC - IL · 316 routing rows
  • CELLCO PARTNERSHIP DBA VERIZON WIRELESS - IL · 293 routing rows
  • BANDWIDTH.COM CLEC, LLC - IL · 174 routing rows
  • ONVOY SPECTRUM, LLC · 82 routing rows
  • PEERLESS NETWORK OF ILLINOIS, LLC - IL · 67 routing rows
  • COMCAST IP PHONE, LLC · 65 routing rows
  • FRACTEL, LLC · 54 routing rows
  • LEVEL 3 COMMUNICATIONS, LLC - IL · 48 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
331-348-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 Chicago, ILLINOIS

June 8, 2026 at 4:56 PM

331-239-9002 was logged as a live voice. Category: Energy, solar, & utilities. Violation date: June 8, 2026 at 3:54 PM.

FTC report from ILLINOIS

June 8, 2026 at 12:07 PM

331-206-1251 was logged as a unwanted call. Category: No Subject Provided. Violation date: June 7, 2026 at 1:00 PM.

FTC report from Kent, WASHINGTON

June 8, 2026 at 10:32 AM

331-266-6091 was logged as a robocall. Violation date: June 5, 2026 at 2:53 PM.

FTC report from ILLINOIS

June 8, 2026 at 9:35 AM

331-305-6260 was logged as a live voice. Category: No Subject Provided. Violation date: June 6, 2026 at 1:55 PM.

FTC report from ILLINOIS

June 7, 2026 at 5:37 PM

331-319-6484 was logged as a unwanted call. Category: No Subject Provided. Violation date: June 7, 2026 at 12:00 AM.

FTC report from ILLINOIS

June 7, 2026 at 2:47 PM

331-205-7352 was logged as a robocall. Violation date: June 7, 2026 at 2:00 PM.

FTC report from Wethersfield, CONNECTICUT

June 6, 2026 at 9:29 PM

331-214-4170 was logged as a robocall. Violation date: June 6, 2026 at 1:22 PM.

FTC report from Bloomington, ILLINOIS

June 6, 2026 at 3:41 PM

331-296-5240 was logged as a robocall. Violation date: April 25, 2026 at 1:12 PM.

FTC report from ILLINOIS

June 6, 2026 at 2:18 PM

331-867-5418 was logged as a unwanted call. Violation date: June 6, 2026 at 9:43 AM.

FTC report from ILLINOIS

June 5, 2026 at 3:47 PM

331-319-6010 was logged as a unwanted call. Category: No Subject Provided. Violation date: June 4, 2026 at 7:02 PM.

FTC report from Conshohocken, PENNSYLVANIA

June 5, 2026 at 2:10 PM

331-200-1484 was logged as a live voice. Violation date: June 5, 2026 at 1:54 PM.

FTC report from Joliet, ILLINOIS

June 5, 2026 at 11:54 AM

331-296-8211 was logged as a live voice. Category: Dropped call or no message. Violation date: June 4, 2026 at 12:15 PM.

FTC report from Rantoul, ILLINOIS

June 5, 2026 at 12:42 AM

331-204-8894 was logged as a live voice. Violation date: June 4, 2026 at 3:11 PM.

FTC report from Red Bud, ILLINOIS

June 4, 2026 at 6:43 PM

331-299-5049 was logged as a robocall. Category: No Subject Provided. Violation date: June 4, 2026 at 9:51 AM.

FTC report from Joliet, ILLINOIS

June 4, 2026 at 5:14 PM

331-257-8046 was logged as a robocall. Category: Dropped call or no message. Violation date: June 4, 2026 at 3:52 PM.

FTC report from Kildeer, MICHIGAN

June 4, 2026 at 4:28 PM

331-288-7971 was logged as a robocall. Category: Dropped call or no message. Violation date: June 4, 2026 at 12:00 AM.

FTC report from Danville, VIRGINIA

June 4, 2026 at 4:13 PM

331-803-4179 was logged as a robocall. Violation date: June 4, 2026 at 3:22 PM.

FTC report from Elk Grove Village, ILLINOIS

June 4, 2026 at 2:10 PM

331-345-6469 was logged as a robocall. Violation date: June 1, 2026 at 1:27 PM.

FTC report from ILLINOIS

June 4, 2026 at 2:09 PM

331-529-9588 was logged as a live voice. Category: Charities. Violation date: June 4, 2026 at 2:08 PM.

FTC report from Elk Grove Village, ILLINOIS

June 4, 2026 at 2:09 PM

331-732-5926 was logged as a unwanted call. Violation date: June 2, 2026 at 9:27 AM.

FTC report from Taylor Ridge, ILLINOIS

June 4, 2026 at 1:06 PM

331-260-0006 was logged as a live voice. Violation date: June 2, 2026 at 2:09 PM.

FTC report from Taylor Ridge, ILLINOIS

June 4, 2026 at 1:05 PM

331-808-1873 was logged as a live voice. Category: Calls pretending to be government, businesses, or family and friends. Violation date: June 4, 2026 at 11:45 AM.

FTC report from Taylor Ridge, ILLINOIS

June 4, 2026 at 1:04 PM

331-808-2355 was logged as a live voice. Category: Calls pretending to be government, businesses, or family and friends. Violation date: June 4, 2026 at 11:59 AM.

FTC report from New Lenox, ILLINOIS

June 4, 2026 at 12:26 PM

331-296-8209 was logged as a live voice. Violation date: June 4, 2026 at 11:23 AM.

FTC report from Joliet, ILLINOIS

June 4, 2026 at 10:51 AM

331-215-5858 was logged as a live voice. Category: Dropped call or no message. Violation date: June 1, 2026 at 6:35 PM.

FTC report from Denver, COLORADO

June 4, 2026 at 1:41 AM

331-373-3631 was logged as a robocall. Violation date: June 3, 2026 at 6:27 PM.

FTC report from KANSAS

June 3, 2026 at 8:30 PM

331-252-7619 was logged as a live voice. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: May 29, 2026 at 12:00 AM.

FTC report from Yorkville, ILLINOIS

June 3, 2026 at 5:35 PM

331-290-5725 was logged as a live voice. Violation date: June 3, 2026 at 3:37 PM.

FTC report from ILLINOIS

June 3, 2026 at 4:57 PM

331-215-5531 was logged as a live voice. Category: Dropped call or no message. Violation date: June 2, 2026 at 5:50 PM.

FTC report from Plainfield, ILLINOIS

June 3, 2026 at 3:06 PM

331-241-6882 was logged as a live voice. Violation date: June 3, 2026 at 12:37 PM.

FTC report from Orland Park, ILLINOIS

June 3, 2026 at 12:23 PM

331-266-6853 was logged as a unwanted call. Category: Dropped call or no message. Violation date: June 1, 2026 at 2:39 PM.

FTC report from ILLINOIS

June 3, 2026 at 10:43 AM

331-268-3134 was logged as a unwanted call. Category: No Subject Provided. Violation date: June 3, 2026 at 9:35 AM.

FTC report from Brick, NEW JERSEY

June 3, 2026 at 8:25 AM

331-373-3169 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: June 1, 2026 at 2:16 PM.

FTC report from Brick, NEW JERSEY

June 3, 2026 at 8:24 AM

331-373-3169 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: June 1, 2026 at 2:16 PM.

FTC report from Summerville, SOUTH CAROLINA

June 2, 2026 at 8:12 PM

331-837-4315 was logged as a robocall. Category: Reducing your debt (credit cards, mortgage, student loans). Violation date: May 28, 2026 at 11:04 AM.

FTC report from Bloomington, ILLINOIS

June 2, 2026 at 5:26 PM

331-296-5182 was logged as a robocall. Violation date: April 22, 2026 at 9:22 AM.

FTC report from Joliet, ILLINOIS

June 2, 2026 at 3:19 PM

331-215-5858 was logged as a live voice. Violation date: June 2, 2026 at 1:03 PM.

FTC report from Joliet, ILLINOIS

June 2, 2026 at 1:35 PM

331-305-6114 was logged as a live voice. Category: Energy, solar, & utilities. Violation date: June 2, 2026 at 12:31 PM.

FTC report from Chicago, ILLINOIS

June 2, 2026 at 4:46 AM

331-808-9038 was logged as a live voice. Violation date: June 1, 2026 at 8:14 PM.

FTC report from Chicago, ILLINOIS

June 1, 2026 at 3:57 PM

331-946-3256 was logged as a robocall. Violation date: May 30, 2026 at 10:34 AM.