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Area Code 312

Illinois · Central time · now 2:41 PM

⚠

Area code 312 is a real Illinois area code

Calls from 312 normally come from Illinois — 7 cities across 2 counties, in the Central time zone. Our archive holds 4,426 caller reports on 1,068 numbers in this area code.

  • A valid area code is not a guarantee — any number can be spoofed to look local.
  • If the caller claims to be your bank or a government agency, hang up and dial the number printed on your card or their official site.

Check the exact number that called you

An area code only tells you the region. Search the full number to see listings and reports for it.

ILstate
7cities served
41carriers
2:41 PMlocal time

Where is area code 312?

Area code 312 serves Illinois, covering Chicago, Prospect Heights, Western Springs, Brookfield, Glenview. In total our directory records 800 phone prefixes in this area code, spread across 7 cities and 2 counties.

The area code sits in the Central time zone (UTC-06:00), where the local time is now approximately 2:41 PM. The oldest prefix on record here entered service on 1994-02-04, and the newest on 2015-09-25.

Of the prefixes with a known line type, 34% are wireless and 66% landline — 252 mobile against 479 fixed-line prefixes.

Area code 312 on the map

Illinois is highlighted below. Schematic map — each square is one state or territory.

AKMEVTNHWAIDMTNDMNILWIMINYRIMAORNVWYSDIAINOHPANJCTCAUTCONEMOKYWVVAMDDEAZNMKSARTNNCSCDCOKLAMSALGAHITXFLPRVI

Line types in this area code

Landline prefixes479 · 66%
Wireless prefixes252 · 34%
Time zoneCentral
UTC offset-06:00
In service since1994
Counties covered2

Carriers operating in area code 312

Telephone companies holding prefixes in this area code, ranked by how many they operate.

CarrierLine typePrefixes
Ameritech IllinoisLandline327
New Cingular Wireless Pcs, LlcWireless76
Cellco Partnership Dba Verizon WirelessWireless50
Usa Mobility Wireless, Inc.Wireless41
T-Mobile Usa, Inc.Wireless25
Sprint Spectrum L.p.Wireless23
Broadwing Communications, LlcLandline20
American Messaging Services, LlcWireless18
Mcimetro Access Transmission Services LlcLandline16
Teleport Communications America, LlcLandline11
Ovation Communications Of Illinois, Inc.Landline9
Allegiance Telecom, Inc.Landline9
Ameritech IllinoisWireless8
Rcn Telecom Services Of Illinois, Inc.Landline8
Mci Worldcom Communications, Inc.Landline8

Cities in area code 312

Places served by this area code, with the number of prefixes assigned to each.

Chicago695 prefixes · CookProspect Heights12 prefixes · CookWestern Springs11 prefixes · CookBrookfield8 prefixes · CookGlenview2 prefixes · CookMedinah2 prefixes · DupageNorthbrook1 prefixes · Cook

Caller reports for area code 312

Aggregated from 4,426 reports covering 1,068 distinct numbers in this area code (2015–2017 archive).

Reported call types

Unknown1,987Telemarketer1,065Debt Collector308Prank Caller60Prank Call59Survey51Political Call39SMS27

Most reported numbers

312-775-128840 reports312-922-650039 reports312-201-680138 reports312-526-410637 reports312-380-541637 reports312-962-468037 reports312-201-462336 reports312-465-110436 reports

Who callers said they were

Names people entered when reporting a call from this area code.

Unknown ×38Norc U Chicago ×34IRS ×25IPSOS ×16Scammer ×16? ×16Synovate ×15N/A ×13Marie Brighton ×13Harris &amp- Harris ×11Don't know ×11cash advance ×11

Report activity by year

20152,060 · 87%
20162,366 · 100%

Numbers reported in area code 312

Each number below was reported by someone who received a call from it. “Reported as” is the name the caller gave or that the recipient recognised — what people wrote down, not verified ownership.

NumberReportsCall typeReported asLast report
312-775-128840Survey, Telemarketer, UnknownMarie Brighton / Survey company / Synovate / Synovate online surveys2016-05-01
312-922-650039Debt Collector, Unknown??2016-04-30
312-201-680138Political Call, Telemarketer, UnknownCenter For Disease Control? / immunization info / NORC U CHICAGO2016-04-27
312-526-410637Survey, Telemarketer, UnknownIPSOS / ipsos marketing. / Scammer / Scammers2016-04-23
312-380-541637Telemarketer, UnknownMarketing / Turn Key Solutions / TurnKey Solutions2016-05-02
312-962-468037Telemarketer, UnknownILLINOIS CALL / synovate2016-04-17
312-201-462336Telemarketer, UnknownCenter for Disease Control Survey / norc u2016-05-02
312-465-110436Telemarketer, UnknownESG Research / Jennifer from ESG Research2016-04-19
312-775-128736Prank Caller, Telemarketer, UnknownIpsos / Synovate2016-04-19
312-640-255235Telemarketer, UnknownTelesight Inc.2016-04-26
312-640-394435Prank Caller, Telemarketer, UnknownA&amp-E - Survey / Home Depot Survey / Sears - Survey2016-04-26
312-529-971734Telemarketer, Unknown—2016-05-01
312-216-877434Telemarketer, UnknownAngel with College Advisors2016-05-01
312-805-513933Unknown—2016-04-30
312-465-352032Telemarketer, Unknown—2016-04-18
312-802-363932Telemarketer, UnknownRatliff Clarence2016-04-21
312-951-127632Survey, Telemarketer, UnknownSears / Sears Survey2016-04-30
312-765-746032Telemarketer, UnknownESG Research Group2016-04-24
312-683-957630Telemarketer, UnknownJessie / S Engine / TBD2016-04-30
312-759-529830Political Call, Telemarketer, UnknownNORC U CHICAGO2016-04-29
312-473-991428Telemarketer, Unknown—2016-04-19
312-759-489928Telemarketer, UnknownCenter for Disease Conrtol supposedly / National Pamdemic Survey / STEVE SLAGLE2016-04-29
312-625-923728Prank Caller, Telemarketer, Unknown—2016-04-09
312-473-982827Debt Collector, Prank Call, Prank Caller, Telemarketer, UnknownGreen dot / PUNJABI'S2016-04-24
312-912-982327Prank Caller, Telemarketer, UnknownCash Advance USA2016-04-18
312-327-969026Telemarketer, UnknownEd-Quest Info / Ed?Quest Info2016-04-25
312-506-368822Telemarketer, UnknownLandmark Mer / Landmark Merchants / Landmark Solutions2016-05-02
312-724-702121Telemarketer, Unknownnatinoal consumer protection server / national sonsumer protection service / National Warranty Center / National Warranty Services2016-04-08
312-489-831221Debt Collector, Telemarketer, UnknownCash Advance USA2016-05-01
312-428-604121Prank Caller, Telemarketer, Unknowndrug scam / patient care group2016-05-01
312-473-984120Prank Caller, Telemarketer, Unknown—2016-05-02
312-777-659020Prank Caller, Telemarketer, UnknownKaplan University (Online)2016-04-23
312-410-885220Telemarketer, UnknownID'd as Online Pharmacy2016-04-28
312-291-483220Prank Call, SMS, Telemarketer, Unknown"Windows" / Anonymous / Brill Street / Brill Street L2016-04-25
312-563-161619Telemarketer, Unknown—2016-04-14
312-473-706119Telemarketer, UnknownMatt2016-03-22
312-724-678619Telemarketer, Unknown—2016-04-21
312-416-418219Telemarketer, UnknownUnited Stationers Supply Company2016-05-02
312-724-581219Telemarketer, Unknown—2016-04-30
312-924-148518Debt Collector, Prank Call, Prank Caller, Unknown"IRS" / ?? / ICENET / IRS2016-04-15
312-578-701518Telemarketer, UnknownCDC Surveys2016-04-18
312-683-969318Telemarketer, UnknownLPUW OFFERS2016-04-26
312-940-693717Debt Collector, Telemarketer, UnknownTelemarketing2016-04-27
312-588-724817Telemarketer, Unknown—2016-04-16
312-624-617416Debt Collector, Telemarketer, UnknownA Harris Law PC / A S Harris Law / Arnold Scott Harris PC. / AS Harris Law2016-04-27
312-962-412516Unknown—2016-04-24
312-568-219916Telemarketer, UnknownIADT2016-03-24
312-604-551916Telemarketer, UnknownDid not say / ECHO / Echo Freight / echo global2016-04-03
312-554-601516Telemarketerfireyourbossnextweek.com / Jumaane / Jumani / Jumani Frisbee2016-05-02
312-940-428616Telemarketer, UnknownCHICAGOZNO1 / ChicGozn01 / Chicgozno1 / Com Ed2016-04-01
312-614-111716Telemarketer, UnknownWoman Support2016-04-29
312-986-998816Debt Collector, Telemarketer, Unknown—2016-04-16
312-775-129316Debt Collector, Telemarketer, UnknownCredit Bureau Enterprises2016-04-29
312-489-821516Survey, Telemarketer, UnknownLocation: Chicago, IL / Manufacturer's Guide / Manufacturers Guide / Manufacturing News2016-04-27
312-473-297415Debt Collector, Prank Caller, Telemarketer, UnknownCash advance / Cash advance place / FHA2016-04-07
312-506-368015Telemarketer, UnknownBluePay / Don't know... / don't know...butwas from this number / landmark2016-05-02
312-205-010915Telemarketer, UnknownVenali,Inc HQ2016-05-01
312-473-990115Telemarketer, Unknown—2016-04-25
312-912-914415Debt Collector, Telemarketer, UnknownSTEVEN2016-04-14
312-957-568715Prank Caller, Telemarketer, Unknown—2016-04-29

Showing the 60 most-reported of 1,068 numbers on record for this area code.

Businesses with 312 numbers

Our business records list 50,362 companies reachable on a 312 number, across 651 cities and 3,758 lines of business. If an unexpected call came from this area code, it may well be one of them.

What they do

General Practice Attorney, Lawyer 2,517Legal Services 1,656Business Consulting, Nec 1,145Business Services, Nec 883General Practice Law Office 882Nonclassifiable Establishments 873Charitable Organization 747Investors, Nec 615Services, Nec 585Management Services 506Real Estate Brokers And Agents 490Design Services 461Real Estate Agents And Managers 447Eating Places 437Offices And Clinics Of Medical Doctors 434

Larger organisations on 312 numbers

Headcount and founding year are as recorded in the business register, and a business may hold a number outside the state it operates in.

BusinessPhoneCityIndustryStaffFounded
Nlfh Acct Payable Bill Ch312-926-2094ChicagoAccounting, Auditing, And Bookkeeping7,0002011
AON Hewitt LLC312-381-1000ChicagoHuman Resource Consulting Services6,6001982
Smx, LLC312-915-0900ChicagoExecutive Placement6,0502011
The Catholic Church Extension Society of The United States of America312-236-7240ChicagoCatholic Church6,0401905
AON Solutions, Inc.312-381-1000ChicagoInsurance Brokers, Nec6,0001898
AON Solutions, Inc.312-381-1000ChicagoInsurance Brokers, Nec6,0001898
Northwestern Memorial Hospital312-755-0604ChicagoGeneral Medical And Surgical Hospitals5,3001867
United Center Joint Venture312-455-4112ChicagoSports Field Or Stadium Operator, Promoting Sports Events4,9991994
Arcelormittal USA LLC312-899-3400East ChicagoWholesale - Steel4,850—
Bmo Bankcorp, Inc.312-461-2121ChicagoNational Commercial Banks4,2001984
Cook County Bureau of Health Services312-864-7571ChicagoGovernment - Administration Of Public Health Programs, County Government4,1141996
CNA Foundation312-822-5000ChicagoFire, Marine, And Casualty Insurance4,0001999
Healthcare Service Corporation312-653-6000ChicagoHospital And Medical Service Plans4,0001936
Chicago Transit Authority312-664-7200ChicagoLocal And Suburban Transit3,724—
Mayer Brown LLP312-782-0600ChicagoGeneral Practice Law Office3,431—
Loyola University of Chicago312-915-7500ChicagoElementary And Secondary Schools3,407—
Stone Southwest, Inc312-346-6600ChicagoManufacturing - Linerboard3,4002012
Accretive Health, Inc.312-324-7820ChicagoHospital Management3,0302003
University of Illinois312-996-9305ChicagoColleges And Universities3,000—
American Casualty Company of Reading, Pennsylvania Inc312-822-5000ChicagoInsurance Agents, Brokers, And Service3,0001902
Chicago Tribune Company312-222-3232ChicagoManufacturing - Newspapers, Publishing And Printing2,7001967
Cook County Bureau of Health Services312-572-2000ChicagoGovernment - Administration Of Public Health Programs, County Government2,533—
Kpmg LLP312-665-1000ChicagoCertified Public Accountant2,500—
County of Cook312-603-5500ChicagoExecutive Offices2,3001831
Ann & Robert H. Lurie Children's Hospital of Chicago Foundation312-227-4000ChicagoMedical Centers2,3001985
BARTON-ASCHMAN ASSOCIATES INC312-930-5100ChicagoEngineering Services2,2001985
National Railroad Passenger Corporation312-655-2422ChicagoInterurban Railways2,046—
City of Chicago312-751-5185ChicagoGovernment - Air, Water, And Solid Waste Management, Local Government2,001—
Professional Convention Management Association312-423-7262ChicagoTrade Associations2,0001958
Children's Hospital of Chicago Medical Center312-227-4000ChicagoHospital, Ama Approved Residency2,0001989
Banta Corporation312-326-8000MenashaCommercial Printing, Nec2,0001901
Veterans Health Administration312-569-8387ChicagoAdministration Of Veterans' Affairs2,000—
Compsych Employee Assistance Programs, Inc312-595-4000ChicagoPersonnel Management Consultant2,0001990
Bowe Bell + Howell Holdings, Inc.312-541-9300WheelingManufacturing - Mailing, Letter Handling, And Addressing Machines1,7102013
Sargent & Lundy, L.L.C.312-269-2000ChicagoConsulting Engineer1,6001891
Groupon, Inc.312-334-1579ChicagoAdvertising Agencies1,5002008
Harborquest, Inc.312-612-7600ChicagoTemporary Help Service1,5001970
Ernst & Young LLP312-879-2000ChicagoBusiness Management Consultant1,500—
General Electric Capital Corporation312-441-7000ChicagoInvestment Holding Companies, Except Banks1,500—
Information Resources, Inc312-726-1221ChicagoPrepackaged Software1,5002011

Where they are

Chicago 46,052Evanston 132Oak Park 117Granger 96Northbrook 91Skokie 88Naperville 85Glenview 72Arlington Heights 66Highland Park 57Des Plaines 56Park Ridge 55Schaumburg 55Wilmette 48Aurora 44Elmhurst 42Oak Lawn 40Palatine 39Berwyn 39Oak Brook 37

Directory listings in area code 312

1 listing from the YPState archive use this area code.

Philip AntinoneChicago, Illinois312-431-0336

ZIP codes in area code 312

Postal codes recorded against prefixes in this area code.

600156002660062600706008960090601576017260193605136051460522605266055860601606026060360604606056060660607606096061160612606146061560616606196062160623606246062960632606366063760638606476065260653606546065760661606996070160804

Phone prefixes in area code 312

Each prefix (the first three digits after the area code) is assigned to a carrier and a service area. Showing the first 200 of 800.

PrefixCityCountyCarrierTypeIn service
312-200——Ameritech Illinois——
312-201ChicagoCookAmeritech IllinoisLandline2003-11-11
312-202ChicagoCookAmeritech IllinoisLandline1997-04-01
312-203ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-204ChicagoCookAmeritech IllinoisLandline1997-10-11
312-205ChicagoCookAllegiance Telecom, Inc.Landline2000-08-20
312-206ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-207ChicagoCookAmeritech IllinoisLandline1997-10-11
312-208ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-209GlenviewCookCellco Partnership Dba Verizon WirelessWireless1995-02-11
312-210ChicagoCookAmeritech IllinoisLandline2003-11-11
312-211—————
312-212ChicagoCookAmeritech IllinoisLandline2000-10-31
312-213ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-214ChicagoCookAmeritech IllinoisLandline2003-11-11
312-215Prospect HeightsCookNew Cingular Wireless Pcs, LlcWireless1995-02-11
312-216ChicagoCookFirst Communications LlcLandline2012-02-13
312-217ChicagoCookSprint Spectrum L.p.Wireless2003-11-11
312-218ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-219ChicagoCookBandwidth.com Clec, LlcWireless2012-04-10
312-220ChicagoCookAmeritech IllinoisLandline1994-02-04
312-221ChicagoCookSprint Spectrum L.p.Wireless2011-06-17
312-222ChicagoCookAmeritech IllinoisLandline1994-02-04
312-223ChicagoCookAmeritech IllinoisLandline1997-10-11
312-224ChicagoCookBroadwing Communications, LlcLandline1999-10-13
312-225ChicagoCookAmeritech IllinoisLandline1997-10-11
312-226ChicagoCookAmeritech IllinoisLandline1997-10-11
312-227ChicagoCookAmeritech IllinoisLandline2010-09-15
312-228ChicagoCookAmeritech IllinoisLandline1997-10-11
312-229ChicagoCookAmeritech IllinoisLandline2000-06-13
312-230ChicagoCookAmeritech IllinoisLandline1997-10-11
312-231MedinahDupageNew Cingular Wireless Pcs, LlcWireless1996-01-10
312-232ChicagoCookAmerican Messaging Services, LlcWireless2001-04-23
312-233ChicagoCookAmeritech IllinoisLandline1999-10-13
312-234ChicagoCookAmeritech IllinoisLandline1998-01-25
312-235ChicagoCookAmeritech IllinoisLandline2000-01-14
312-236ChicagoCookAmeritech IllinoisLandline2003-11-11
312-237ChicagoCookCellco Partnership Dba Verizon WirelessWireless2000-10-31
312-238ChicagoCookBroadwing Communications, LlcLandline1999-10-13
312-239ChicagoCookAt&t LocalLandline1998-01-25
312-240ChicagoCookAmeritech IllinoisLandline1997-10-11
312-241ChicagoCookNew Cingular Wireless Pcs, LlcWireless2011-08-17
312-242ChicagoCookTeleport Communications America, LlcLandline2000-08-20
312-243ChicagoCookAmeritech IllinoisLandline1997-10-11
312-244ChicagoCookAmeritech IllinoisLandline2000-10-31
312-245ChicagoCookAmeritech IllinoisLandline1997-10-11
312-246Prospect HeightsCookNew Cingular Wireless Pcs, LlcWireless1995-02-11
312-247ChicagoCookFirst Communications LlcLandline2004-04-06
312-248ChicagoCookMetro Pcs, Inc.Wireless2014-07-01
312-249ChicagoCookUsa Mobility Wireless, Inc.Wireless1994-02-04
312-250ChicagoCookUsa Mobility Wireless, Inc.Wireless1994-02-04
312-251ChicagoCookAmeritech IllinoisLandline1997-10-11
312-252ChicagoCookAllegiance Telecom, Inc.Landline1998-01-25
312-253ChicagoCookAllegiance Telecom, Inc.Landline1998-01-25
312-254ChicagoCookAllegiance Telecom, Inc.Landline1998-01-25
312-255ChicagoCookAmeritech IllinoisLandline1997-10-11
312-256ChicagoCookAllegiance Telecom, Inc.Landline1998-01-25
312-257ChicagoCookCellco Partnership Dba Verizon WirelessWireless2011-08-18
312-258ChicagoCookAmeritech IllinoisLandline1997-10-11
312-259ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-260ChicagoCookMcimetro Access Transmission Services LlcLandline1997-04-01
312-261ChicagoCookBroadwing Communications, LlcLandline1999-05-10
312-262ChicagoCookAllegiance Telecom, Inc.Landline1998-01-25
312-263ChicagoCookAmeritech IllinoisLandline1994-02-04
312-264ChicagoCookBroadwing Communications, LlcLandline1999-07-22
312-265ChicagoCookAccess One, Inc.Landline2005-11-29
312-266ChicagoCookAmeritech IllinoisLandline1994-02-04
312-267ChicagoCookAmeritech IllinoisLandline2000-06-13
312-268ChicagoCookBroadwing Communications, LlcLandline2001-03-03
312-269ChicagoCookAmeritech IllinoisLandline1994-02-04
312-270—————
312-271ChicagoCookUsa Mobility Wireless, Inc.Wireless1998-01-25
312-272ChicagoCookUsa Mobility Wireless, Inc.Wireless1996-07-01
312-273ChicagoCookCellco Partnership Dba Verizon WirelessWireless2011-09-13
312-274ChicagoCookAmeritech IllinoisLandline1998-01-25
312-275ChicagoCookAllegiance Telecom, Inc.Landline1998-01-25
312-276ChicagoCookAllegiance Telecom, Inc.Landline1998-01-25
312-277ChicagoCookAllegiance Telecom, Inc.Landline1998-01-25
312-278ChicagoCookBroadwing Communications, LlcLandline2000-10-31
312-279ChicagoCookMcimetro Access Transmission Services LlcLandline1998-01-25
312-280ChicagoCookAmeritech IllinoisLandline1997-10-11
312-281ChicagoCookGlobal Crossing Local Services, Inc.-IlLandline1999-10-13
312-282ChicagoCookNew Cingular Wireless Pcs, LlcWireless2000-10-31
312-283ChicagoCookGlobal Crossing Local Services, Inc.-IlLandline1999-10-13
312-284ChicagoCookXo Illinois, Inc.Landline2001-06-30
312-285ChicagoCookSprint Spectrum L.p.Wireless2001-06-30
312-286ChicagoCookNew Cingular Wireless Pcs, LlcWireless2000-06-13
312-287ChicagoCookSprint Spectrum L.p.Wireless2000-10-31
312-288ChicagoCookMcimetro Access Transmission Services LlcLandline1998-01-25
312-289ChicagoCookUsa Mobility Wireless, Inc.Wireless1994-02-04
312-290ChicagoCookUsa Mobility Wireless, Inc.Wireless2003-11-11
312-291ChicagoCookAmeritech IllinoisLandline2000-06-13
312-292ChicagoCookBandwidth.com Clec, LlcWireless2011-09-02
312-293ChicagoCookAmeritech IllinoisLandline1994-02-04
312-294ChicagoCookAmeritech IllinoisLandline1997-10-11
312-295BrookfieldCookUsa Mobility Wireless, Inc.Wireless1995-02-11
312-296ChicagoCookSprint Spectrum L.p.Wireless2000-01-14
312-297ChicagoCookAmeritech IllinoisLandline1995-02-11
312-298ChicagoCookSigecom, Llc Dba Wow Internet Cable And PhoneLandline1999-07-22
312-299ChicagoCookUsa Mobility Wireless, Inc.Wireless1994-02-04
312-300ChicagoCookNet Talk.com, Inc.Landline2011-04-25
312-301Western SpringsCookNew Cingular Wireless Pcs, LlcWireless1995-02-11
312-302ChicagoCookAmeritech IllinoisLandline1994-02-04
312-303Prospect HeightsCookNew Cingular Wireless Pcs, LlcWireless1995-02-11
312-304Western SpringsCookNew Cingular Wireless Pcs, LlcWireless1995-02-11
312-305NorthbrookCookCellco Partnership Dba Verizon WirelessWireless2003-11-11
312-306ChicagoCookAmeritech IllinoisLandline1994-02-04
312-307ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-308ChicagoCookAmeritech IllinoisLandline1997-10-11
312-309ChicagoCookAmeritech IllinoisLandline2003-11-11
312-310GlenviewCookCellco Partnership Dba Verizon WirelessWireless1995-02-11
312-311—————
312-312—————
312-313ChicagoCookBroadvox-Clec, LlcLandline2014-11-10
312-314Western SpringsCookNew Cingular Wireless Pcs, LlcWireless1994-09-11
312-315ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-316ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-317Prospect HeightsCookNew Cingular Wireless Pcs, LlcWireless1995-02-11
312-318BrookfieldCookCellco Partnership Dba Verizon WirelessWireless1995-02-11
312-319—————
312-320ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-321ChicagoCookAmeritech IllinoisLandline1997-10-11
312-322ChicagoCookAmeritech IllinoisLandline1997-10-11
312-323ChicagoCookAmerican Messaging Services, LlcWireless2001-04-13
312-324ChicagoCookLevel 3 Communications, LlcLandline2001-05-03
312-325ChicagoCookAmeritech IllinoisLandline2003-06-24
312-326ChicagoCookAmeritech IllinoisLandline1994-02-04
312-327ChicagoCookXo Illinois, Inc.Landline2000-08-20
312-328ChicagoCookAmeritech IllinoisLandline1997-10-11
312-329ChicagoCookAmeritech IllinoisLandline1994-02-04
312-330ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-331Prospect HeightsCookNew Cingular Wireless Pcs, LlcWireless1996-01-10
312-332ChicagoCookAmeritech IllinoisLandline1994-02-04
312-333ChicagoCookAmerican Messaging Services, LlcWireless2001-04-13
312-334ChicagoCookFirst Communications LlcLandline2000-10-31
312-335ChicagoCookAmeritech IllinoisLandline1994-02-04
312-336ChicagoCookAmeritech IllinoisLandline2003-11-11
312-337ChicagoCookAmeritech IllinoisLandline1994-02-04
312-338ChicagoCookAmeritech IllinoisLandline1997-04-01
312-339ChicagoCookCellco Partnership Dba Verizon WirelessWireless2003-11-11
312-340ChicagoCookCellco Partnership Dba Verizon WirelessWireless2011-09-21
312-341ChicagoCookAmeritech IllinoisLandline1997-10-11
312-342ChicagoCookNew Cingular Wireless Pcs, LlcWireless2001-06-30
312-343ChicagoCookCellco Partnership Dba Verizon WirelessWireless2003-11-11
312-344ChicagoCookAmeritech IllinoisLandline1997-07-06
312-345ChicagoCookAmeritech IllinoisLandline2003-11-11
312-346ChicagoCookAmeritech IllinoisLandline2003-11-11
312-347ChicagoCookAmeritech IllinoisLandline1994-02-04
312-348ChicagoCookNeutral Tandem-Illinois, LlcLandline2003-11-14
312-349ChicagoCookUsa Mobility Wireless, Inc.Wireless1994-02-04
312-350ChicagoCookCellco Partnership Dba Verizon WirelessWireless2003-11-11
312-351ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-352Western SpringsCookNew Cingular Wireless Pcs, LlcWireless1995-07-04
312-353ChicagoCookAmeritech IllinoisLandline1994-02-04
312-354MedinahDupageNew Cingular Wireless Pcs, LlcWireless1996-01-10
312-355ChicagoCookAmeritech IllinoisLandline1995-07-04
312-356ChicagoCookAmeritech IllinoisLandline2000-01-14
312-357ChicagoCookAmeritech IllinoisLandline1997-10-11
312-358——T-Mobile Usa, Inc.—2015-07-21
312-359ChicagoCookUsa Mobility Wireless, Inc.Wireless1995-07-04
312-360ChicagoCookAmeritech IllinoisLandline1994-02-04
312-361ChicagoCookAmeritech IllinoisLandline2000-10-31
312-362ChicagoCookAmeritech IllinoisLandline1997-10-11
312-363ChicagoCookRcn Telecom Services Of Illinois, Inc.Landline1999-05-10
312-364ChicagoCookAmeritech IllinoisLandline1994-09-11
312-365ChicagoCookUsa Mobility Wireless, Inc.Wireless2003-11-11
312-366————1996-01-10
312-367BrookfieldCookUsa Mobility Wireless, Inc.Wireless2003-11-11
312-368ChicagoCookAmeritech IllinoisLandline1994-02-04
312-369ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-370ChicagoCookUsa Mobility Wireless, Inc.Wireless2003-11-11
312-371ChicagoCookSprint Spectrum L.p.Wireless1998-01-25
312-372ChicagoCookAmeritech IllinoisLandline2003-11-11
312-373ChicagoCookBroadwing Communications, LlcLandline1999-05-10
312-374ChicagoCookAmeritech IllinoisLandline1999-10-13
312-375ChicagoCookT-Mobile Usa, Inc.Wireless2001-06-30
312-376ChicagoCookCbeyond Communications, LlcLandline2004-06-11
312-377ChicagoCookXo Illinois, Inc.Landline1998-01-25
312-378ChicagoCookUsa Mobility Wireless, Inc.Wireless1998-01-25
312-379ChicagoCookOvation Communications Of Illinois, Inc.Landline2001-04-10
312-380ChicagoCookAmeritech IllinoisLandline2000-08-20
312-381ChicagoCookAmeritech IllinoisLandline1999-05-10
312-382ChicagoCookAmeritech IllinoisLandline1994-02-04
312-383————1996-01-10
312-384ChicagoCookAmeritech IllinoisLandline1999-10-13
312-385ChicagoCookAmeritech IllinoisLandline1998-01-25
312-386ChicagoCookAmeritech IllinoisLandline2000-08-20
312-387ChicagoCookUsa Mobility Wireless, Inc.Wireless1994-02-04
312-388ChicagoCookSprint Spectrum L.p.Wireless1998-01-25
312-389ChicagoCookUsa Mobility Wireless, Inc.Wireless2003-11-11
312-390ChicagoCookAmerican Messaging Services, LlcWireless2001-04-16
312-391ChicagoCookNew Cingular Wireless Pcs, LlcWireless2003-11-11
312-392—————
312-393ChicagoCookAmerican Messaging Services, LlcWireless2001-04-23
312-394ChicagoCookAmeritech IllinoisLandline1994-02-04
312-395ChicagoCookAt&t LocalLandline1998-01-25
312-396ChicagoCookAmeritech IllinoisLandline1994-02-04
312-397ChicagoCookAmeritech IllinoisLandline1997-10-11
312-398ChicagoCookUsa Mobility Wireless, Inc.Wireless1996-01-10
312-399ChicagoCookSprint Spectrum L.p.Wireless1999-07-22

Frequently asked questions

Where is area code 312?

Area code 312 serves Illinois, including Chicago. It covers 7 cities across 2 counties, in the Central time zone.

What time is it in area code 312?

Area code 312 observes Central time (UTC-06:00). The current local time is approximately 2:41 PM.

When was area code 312 introduced?

The earliest phone prefix recorded in area code 312 was put in service on 1994-02-04. The most recent was activated on 2015-09-25.

Is a call from 312 safe to answer?

Our directory holds 4,426 caller reports covering 1,068 numbers in area code 312. A valid area code does not guarantee a legitimate caller, since numbers can be spoofed.

What cities are in area code 312?

The largest places served by area code 312 are Chicago, Prospect Heights, Western Springs, Brookfield, Glenview, Medinah, Northbrook. In total it covers 7 cities across 2 counties.

How is a 312 phone number written?

A number in this area code is written +1 (312) XXX-XXXX in international format, or (312) XXX-XXXX domestically. The +1 is the country code shared by the United States, Canada and other NANP members.

Can scammers fake a 312 number?

Yes. Caller ID was built without verification, so a caller can display almost any number. Scammers often pick a number matching the area code of the person they are calling — known as neighbour spoofing — because a local-looking call is answered more often. The US industry response, STIR/SHAKEN, lets carriers sign and verify caller ID, but coverage is still incomplete.

Why do I get calls from numbers with my own area code?

Almost always neighbour spoofing: the caller fabricates a number sharing your area code, and sometimes your prefix, so the call looks like it comes from someone nearby. A matching area code is not evidence that the caller is local.

How do I report a spam call from 312?

Report unwanted calls to the FTC at reportfraud.ftc.gov, and add your number to the Do Not Call registry at donotcall.gov. Include the caller ID number even if you believe it was spoofed — regulators use the pattern of reports, not the individual number.

Other area codes in Illinois

Area code 217236 citiesArea code 22449 citiesArea code 309156 citiesArea code 33122 citiesArea code 618215 citiesArea code 63043 citiesArea code 70856 citiesArea code 77318 citiesArea code 77937 citiesArea code 815177 citiesArea code 84756 citiesArea code 8721 cities

Where this data comes from

Different parts of this page carry different levels of reliability. Here is what each one rests on.

DataBased onReliabilityCovers
Area code & prefix dataNANPA prefix recordshighcompiled 2018
Caller reportsconsumer-submitted reportsconsumer-reported2015–2017 archive
Directory listingsYPState archivehigh2004–2020
Business recordscommercial business registermediumcompiled 2018

About the caller reports: these were submitted by members of the public and are not verified. They record what a caller ID displayed and what the recipient made of the call — they are not proof of who owns a number, and because caller ID can be faked, a reported number may have nothing to do with the person actually calling.

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