Area Code +1-312-(2523000...2523999) 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 : 2523000 Subscriber Number To : 2523999 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 : ALLEGIANCE TELCOM IL 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-(2522000...2522999) next › : +1-312-(2524000...2524999) Dialling Instructions For trunk calls: 0 312 2523000 (Trunk Code + National Destination Code + Subscriber Number) For international calls: 011 1 312 2523000 (International Prefix + International Dailing Code +National Destination Code + Subscriber Number) Telephone Number List 2523000 ~ 2523999 (Count: 1,000) Example: +1-312-2523000 / 0111-312-2523000 (1312-2523000 / 1-312-2523000) +1-312-2523001 / 0111-312-2523001 (1312-2523001 / 1-312-2523001) +1-312-2523002 / 0111-312-2523002 (1312-2523002 / 1-312-2523002) +1-312-2523003 / 0111-312-2523003 (1312-2523003 / 1-312-2523003) +1-312-2523004 / 0111-312-2523004 (1312-2523004 / 1-312-2523004) ...+1-312-xxxxxxx / 0111-312-xxxxxxx (1312-xxxxxxx / 1-312-xxxxxxx) ...+1-312-2523995 / 0111-312-2523995 (1312-2523995 / 1-312-2523995) +1-312-2523996 / 0111-312-2523996 (1312-2523996 / 1-312-2523996) +1-312-2523997 / 0111-312-2523997 (1312-2523997 / 1-312-2523997) +1-312-2523998 / 0111-312-2523998 (1312-2523998 / 1-312-2523998) +1-312-2523999 / 0111-312-2523999 (1312-2523999 / 1-312-2523999)