District of Illinois area codes: 312 | |
---|---|
Country | United States |
State/Province | Illinois |
Major City | Chicago |
Time Zone | Central (UTC-06:00) |
Prefix | County | Primary City | Company |
---|---|---|---|
312-974 | Cook | Chicago, IL | Ameritech Illinois |
312-977 | Cook | Chicago, IL | Ameritech Illinois |
312-978 | Cook | Chicago, IL | T-mobile Usa |
312-979 | Cook | Chicago, IL | Ameritech Illinois |
312-980 | Cook | Chicago, IL | Teleport Communications America |
312-981 | Cook | Chicago, IL | Ovation Communications Of Illinois |
312-983 | Cook | Chicago, IL | Ameritech Illinois |
312-984 | Cook | Chicago, IL | Ameritech Illinois |
312-985 | Cook | Chicago, IL | Ovation Communications Of Illinois |
312-986 | Cook | Chicago, IL | Ameritech Illinois |
312-987 | Cook | Chicago, IL | Ameritech Illinois |
312-988 | Cook | Chicago, IL | Ameritech Illinois |
312-990 | Dupage | Hinsdale, IL | New Cingular Wireless PCS |
312-991 | Cook | Wheeling, IL | New Cingular Wireless PCS |
312-992 | Cook | Chicago, IL | Ameritech Illinois |
312-993 | Cook | Chicago, IL | Ameritech Illinois |
312-994 | Cook | Chicago, IL | Ovation Communications Of Illinois |
312-996 | Cook | Chicago, IL | Ameritech Illinois |
312-997 | Cook | Chicago, IL | Ameritech Illinois |
312-999 | Cook | Chicago, IL | Xo Illinois |
There are 701 prefixes, In the code area, the major cities are Chicago, IL. The major city is Chicago.