Area Code +1-312-(2020000...2020999) located in Chicago, Illinois (IL), more detail is as below. Place International Dialing Code : 1 International Prefix : 011 National Prefix : 1 National Destination Code : 312 Subscriber Number From : 2020000 Subscriber Number To : 2020999 National Destination Code Length : 3 Uses National Destination Code : Yes National Significant Number Length : 10 Number Type : G (Geographic Land Line, Fixed Line) Carrier Name : AMERITECH ILLINOIS Click here to buy United States Area Code Database Other Information Language Code : en (English) Country Number : 840 (United States) Country Code : US (United States) Region Code : IL Region Name : Illinois City : Chicago Timezone : America/Chicago Coordinated Universal Time : -06:00 Daylight Saving Time : Yes National Significant Number Minimum Length : 10 Latitude : 41.8800 Longitude : -87.6400 ‹ previous : +1-312-(2010000...2019999) next › : +1-312-(2021000...2021999) Dialling Instructions For trunk calls: 0 312 2020000 (Trunk Code + National Destination Code + Subscriber Number) For international calls: 011 1 312 2020000 (International Prefix + International Dailing Code +National Destination Code + Subscriber Number) Telephone Number List 2020000 ~ 2020999 (Count: 1,000) Example: +1-312-2020000 / 0111-312-2020000 (1312-2020000 / 1-312-2020000) +1-312-2020001 / 0111-312-2020001 (1312-2020001 / 1-312-2020001) +1-312-2020002 / 0111-312-2020002 (1312-2020002 / 1-312-2020002) +1-312-2020003 / 0111-312-2020003 (1312-2020003 / 1-312-2020003) +1-312-2020004 / 0111-312-2020004 (1312-2020004 / 1-312-2020004) ...+1-312-xxxxxxx / 0111-312-xxxxxxx (1312-xxxxxxx / 1-312-xxxxxxx) ...+1-312-2020995 / 0111-312-2020995 (1312-2020995 / 1-312-2020995) +1-312-2020996 / 0111-312-2020996 (1312-2020996 / 1-312-2020996) +1-312-2020997 / 0111-312-2020997 (1312-2020997 / 1-312-2020997) +1-312-2020998 / 0111-312-2020998 (1312-2020998 / 1-312-2020998) +1-312-2020999 / 0111-312-2020999 (1312-2020999 / 1-312-2020999)