312 Area Code

State: Illinois

Major City: Springfield

  • Admission to Statehood:
    December 3, 1818 (21st State)
  • Constitution:
    Illinois's Constitution , 21st State
  • Nickname:
    Prairie State
  • Population (2013):
    12,882,135; Rank: 5 of 50 | Population Quick Facts

Area:

  • Area: 57,918 sq.mi (150,007 sq.km.), 25th
  • Land: 55,593 sq.mi. (143,985 sq.km.), 24th
  • Water: 2,325 sq.mi. (6,022 sq.km.), 20th
  • Great Lakes: 2,546 sq.mi. (6,594 sq.km.),tied for 5th

Area Code 312

Map:

Area Code Prefix Usage Primary City Carrier Introduced
312 (312) 201- Landline Chicago Ameritech Illinois 11/11/2003
312 (312) 202- Landline Chicago Ameritech Illinois 04/01/1997
312 (312) 203- Wireless Chicago New Cingular Wireless PCS 11/11/2003
312 (312) 204- Landline Chicago Ameritech Illinois 10/11/1997
312 (312) 205- Landline Chicago Allegiance Telecom 08/20/2000
312 (312) 206- Wireless Chicago New Cingular Wireless PCS 11/11/2003
312 (312) 207- Landline Chicago Ameritech Illinois 10/11/1997
312 (312) 208- Wireless Chicago New Cingular Wireless PCS 11/11/2003
312 (312) 209- Wireless Northbrook Cellco Partnership DBA Verizon Wireless 02/11/1995
312 (312) 212- Landline Chicago Ameritech Illinois 10/31/2000
312 (312) 213- Wireless Chicago New Cingular Wireless PCS 11/11/2003
312 (312) 214- Landline Chicago Ameritech Illinois 11/11/2003
312 (312) 215- Wireless Wheeling New Cingular Wireless PCS 02/11/1995
312 (312) 216- Landline Chicago First Communications LLC 02/13/2012
312 (312) 217- Wireless Chicago United States Cellular Corp. - Illinois 11/11/2003
312 (312) 218- Wireless Chicago New Cingular Wireless PCS 11/11/2003
312 (312) 219- Wireless Chicago Bandwidth.com Clec 04/10/2012
312 (312) 220- Landline Chicago Ameritech Illinois 02/04/1994
312 (312) 221- Wireless Chicago Sprint Spectrum L.p. 06/17/2011
312 (312) 222- Landline Chicago Ameritech Illinois 02/04/1994
312 (312) 223- Landline Chicago Ameritech Illinois 10/11/1997
312 (312) 224- Landline Chicago Broadwing Communications 10/13/1999
312 (312) 225- Landline Chicago Ameritech Illinois 10/11/1997
312 (312) 226- Landline Chicago Ameritech Illinois 10/11/1997
312 (312) 227- Landline Chicago Ameritech Illinois 09/15/2010
312 (312) 228- Landline Chicago Ameritech Illinois 10/11/1997
312 (312) 229- Landline Chicago Ameritech Illinois 06/13/2000
312 (312) 230- Landline Chicago Ameritech Illinois 10/11/1997
312 (312) 231- Wireless Roselle New Cingular Wireless PCS 01/10/1996
312 (312) 232- Wireless Chicago American Messaging (am) 04/23/2001
312 (312) 233- Landline Chicago Ameritech Illinois 10/13/1999
312 (312) 234- Landline Chicago Ameritech Illinois 01/25/1998
312 (312) 235- Landline Chicago Ameritech Illinois 01/14/2000
312 (312) 236- Landline Chicago Ameritech Illinois 11/11/2003
312 (312) 237- Wireless Chicago Cellco Partnership DBA Verizon Wireless 10/31/2000
312 (312) 238- Landline Chicago Broadwing Communications 10/13/1999
312 (312) 239- Landline Chicago AT&T; Local 01/25/1998
312 (312) 240- Landline Chicago Ameritech Illinois 10/11/1997
312 (312) 241- Wireless Chicago New Cingular Wireless PCS 08/17/2011
312 (312) 242- Landline Chicago Teleport Communications America 08/20/2000
312 (312) 243- Landline Chicago Ameritech Illinois 10/11/1997
312 (312) 244- Landline Chicago Ameritech Illinois 10/31/2000
312 (312) 245- Landline Chicago Ameritech Illinois 10/11/1997
312 (312) 246- Wireless Wheeling New Cingular Wireless PCS 02/11/1995
312 (312) 247- Landline Chicago First Communications LLC 04/06/2004
312 (312) 248- Unknown Metro PCS 07/01/2014
312 (312) 249- Wireless Chicago Usa Mobility Wireless 02/04/1994
312 (312) 250- Wireless Chicago Usa Mobility Wireless 02/04/1994
312 (312) 251- Landline Chicago Ameritech Illinois 10/11/1997
312 (312) 252- Landline Chicago Allegiance Telecom 01/25/1998
Area Code: 312
Prefix: (312) 201-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 11/11/2003
Area Code: 312
Prefix: (312) 202-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 04/01/1997
Area Code: 312
Prefix: (312) 203-
Usage: Wireless
Primary City: Chicago
Carrier: New Cingular Wireless PCS
Introduced: 11/11/2003
Area Code: 312
Prefix: (312) 204-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/11/1997
Area Code: 312
Prefix: (312) 205-
Usage: Landline
Primary City: Chicago
Carrier: Allegiance Telecom
Introduced: 08/20/2000
Area Code: 312
Prefix: (312) 206-
Usage: Wireless
Primary City: Chicago
Carrier: New Cingular Wireless PCS
Introduced: 11/11/2003
Area Code: 312
Prefix: (312) 207-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/11/1997
Area Code: 312
Prefix: (312) 208-
Usage: Wireless
Primary City: Chicago
Carrier: New Cingular Wireless PCS
Introduced: 11/11/2003
Area Code: 312
Prefix: (312) 209-
Usage: Wireless
Primary City: Northbrook
Carrier: Cellco Partnership DBA Verizon Wireless
Introduced: 02/11/1995
Area Code: 312
Prefix: (312) 212-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/31/2000
Area Code: 312
Prefix: (312) 213-
Usage: Wireless
Primary City: Chicago
Carrier: New Cingular Wireless PCS
Introduced: 11/11/2003
Area Code: 312
Prefix: (312) 214-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 11/11/2003
Area Code: 312
Prefix: (312) 215-
Usage: Wireless
Primary City: Wheeling
Carrier: New Cingular Wireless PCS
Introduced: 02/11/1995
Area Code: 312
Prefix: (312) 216-
Usage: Landline
Primary City: Chicago
Carrier: First Communications LLC
Introduced: 02/13/2012
Area Code: 312
Prefix: (312) 217-
Usage: Wireless
Primary City: Chicago
Carrier: United States Cellular Corp. - Illinois
Introduced: 11/11/2003
Area Code: 312
Prefix: (312) 218-
Usage: Wireless
Primary City: Chicago
Carrier: New Cingular Wireless PCS
Introduced: 11/11/2003
Area Code: 312
Prefix: (312) 219-
Usage: Wireless
Primary City: Chicago
Carrier: Bandwidth.com Clec
Introduced: 04/10/2012
Area Code: 312
Prefix: (312) 220-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 02/04/1994
Area Code: 312
Prefix: (312) 221-
Usage: Wireless
Primary City: Chicago
Carrier: Sprint Spectrum L.p.
Introduced: 06/17/2011
Area Code: 312
Prefix: (312) 222-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 02/04/1994
Area Code: 312
Prefix: (312) 223-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/11/1997
Area Code: 312
Prefix: (312) 224-
Usage: Landline
Primary City: Chicago
Carrier: Broadwing Communications
Introduced: 10/13/1999
Area Code: 312
Prefix: (312) 225-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/11/1997
Area Code: 312
Prefix: (312) 226-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/11/1997
Area Code: 312
Prefix: (312) 227-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 09/15/2010
Area Code: 312
Prefix: (312) 228-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/11/1997
Area Code: 312
Prefix: (312) 229-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 06/13/2000
Area Code: 312
Prefix: (312) 230-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/11/1997
Area Code: 312
Prefix: (312) 231-
Usage: Wireless
Primary City: Roselle
Carrier: New Cingular Wireless PCS
Introduced: 01/10/1996
Area Code: 312
Prefix: (312) 232-
Usage: Wireless
Primary City: Chicago
Carrier: American Messaging (am)
Introduced: 04/23/2001
Area Code: 312
Prefix: (312) 233-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/13/1999
Area Code: 312
Prefix: (312) 234-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 01/25/1998
Area Code: 312
Prefix: (312) 235-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 01/14/2000
Area Code: 312
Prefix: (312) 236-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 11/11/2003
Area Code: 312
Prefix: (312) 237-
Usage: Wireless
Primary City: Chicago
Carrier: Cellco Partnership DBA Verizon Wireless
Introduced: 10/31/2000
Area Code: 312
Prefix: (312) 238-
Usage: Landline
Primary City: Chicago
Carrier: Broadwing Communications
Introduced: 10/13/1999
Area Code: 312
Prefix: (312) 239-
Usage: Landline
Primary City: Chicago
Carrier: AT&T; Local
Introduced: 01/25/1998
Area Code: 312
Prefix: (312) 240-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/11/1997
Area Code: 312
Prefix: (312) 241-
Usage: Wireless
Primary City: Chicago
Carrier: New Cingular Wireless PCS
Introduced: 08/17/2011
Area Code: 312
Prefix: (312) 242-
Usage: Landline
Primary City: Chicago
Carrier: Teleport Communications America
Introduced: 08/20/2000
Area Code: 312
Prefix: (312) 243-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/11/1997
Area Code: 312
Prefix: (312) 244-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/31/2000
Area Code: 312
Prefix: (312) 245-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/11/1997
Area Code: 312
Prefix: (312) 246-
Usage: Wireless
Primary City: Wheeling
Carrier: New Cingular Wireless PCS
Introduced: 02/11/1995
Area Code: 312
Prefix: (312) 247-
Usage: Landline
Primary City: Chicago
Carrier: First Communications LLC
Introduced: 04/06/2004
Area Code: 312
Prefix: (312) 248-
Usage: Unknown
Primary City:
Carrier: Metro PCS
Introduced: 07/01/2014
Area Code: 312
Prefix: (312) 249-
Usage: Wireless
Primary City: Chicago
Carrier: Usa Mobility Wireless
Introduced: 02/04/1994
Area Code: 312
Prefix: (312) 250-
Usage: Wireless
Primary City: Chicago
Carrier: Usa Mobility Wireless
Introduced: 02/04/1994
Area Code: 312
Prefix: (312) 251-
Usage: Landline
Primary City: Chicago
Carrier: Ameritech Illinois
Introduced: 10/11/1997
Area Code: 312
Prefix: (312) 252-
Usage: Landline
Primary City: Chicago
Carrier: Allegiance Telecom
Introduced: 01/25/1998