Area Code 312
Illinois area code 312 has been in service since 1947. It has 474 landlines and 159 wireless prefixes (exchanges) serviced by 40 carriers. It covers 3 counties, 530 ZIP codes, and 1 city, including Chicago.
- State:
- Illinois
- Time Zone:
- Central (11:26 pm)
Area Code (312) has 633 prefixes
| Prefix | County | City | Company/Carrier | Line Type |
|---|---|---|---|---|
| (312) 201- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 202- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 203- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 204- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 205- | Cook | Chicago | Allegiance Telecom, Inc. - Il | Landline |
| (312) 206- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 207- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 208- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 209- | Cook | Chicago | Cellco Partnership Dba Veri... | Cell Phone |
| (312) 212- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 213- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 214- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 216- | Cook | Chicago | Adbeep, Llc | Cell Phone |
| (312) 217- | Cook | Chicago | United States Cellular Corp. | Cell Phone |
| (312) 218- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 220- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 221- | Cook | Chicago | Heartland Communications, Inc. | Landline |
| (312) 222- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 223- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 224- | Cook | Chicago | Broadwing Communications, L... | Landline |
| (312) 225- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 226- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 227- | Cook | Chicago | Unknown | Landline |
| (312) 228- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 229- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 230- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 231- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 232- | Cook | Berwyn | American Messaging (am), Inc. | Cell Phone |
| (312) 233- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 234- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 235- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 236- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 237- | Cook | Chicago | Cellco Partnership Dba Veri... | Cell Phone |
| (312) 238- | Cook | Chicago | Broadwing Communications, L... | Landline |
| (312) 239- | Cook | Chicago | At&t Local | Landline |
| (312) 240- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 242- | Cook | Chicago | Teleport Communications Gro... | Landline |
| (312) 243- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 244- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 245- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 246- | Cook | Ashburn Park | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 247- | Cook | Chicago | Globalcom, Inc.-il | Landline |
| (312) 248- | Cook | Chicago | Unknown | Landline |
| (312) 250- | Cook | Chicago | Metrocall | Landline |
| (312) 251- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 252- | Cook | Chicago | Allegiance Telecom, Inc. - Il | Landline |
| (312) 253- | Cook | Chicago | Allegiance Telecom, Inc. - Il | Landline |
| (312) 254- | Cook | Chicago | Allegiance Telecom, Inc. - Il | Landline |
| (312) 255- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 256- | Cook | Chicago | Allegiance Telecom, Inc. - Il | Landline |
| (312) 258- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 259- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 260- | Cook | Chicago | Mcimetro, Ats, Inc. | Landline |
| (312) 261- | Cook | Chicago | Broadwing Communications, L... | Landline |
| (312) 262- | Cook | Chicago | Allegiance Telecom, Inc. - Il | Landline |
| (312) 263- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 264- | Cook | Chicago | Broadwing Communications, L... | Landline |
| (312) 265- | Cook | Chicago | Access One, Inc. - Il | Landline |
| (312) 266- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 267- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 268- | Cook | Chicago | Broadwing Communications, L... | Landline |
| (312) 269- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 271- | Cook | Chicago | Arch Wireless Holdings, Inc. | Cell Phone |
| (312) 272- | Cook | Northbrook | Metrocall | Landline |
| (312) 274- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 275- | Cook | Chicago | Allegiance Telecom, Inc. - Il | Landline |
| (312) 276- | Cook | Chicago | Allegiance Telecom, Inc. - Il | Landline |
| (312) 277- | Cook | Chicago | Allegiance Telecom, Inc. - Il | Landline |
| (312) 278- | Cook | Chicago | Broadwing Communications, L... | Landline |
| (312) 279- | Cook | Chicago | Mcimetro, Ats, Inc. | Landline |
| (312) 280- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 281- | Cook | Chicago | Global Crossing Local Servi... | Landline |
| (312) 282- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 283- | Cook | Chicago | Global Crossing Local Servi... | Landline |
| (312) 284- | Cook | Chicago | Xo Illinois, Inc. | Landline |
| (312) 285- | Cook | Chicago | Sprint Spectrum L.p. | Cell Phone |
| (312) 286- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 287- | Cook | Chicago | Nextel Communications, Inc. | Cell Phone |
| (312) 288- | Cook | Chicago | Mcimetro, Ats, Inc. | Landline |
| (312) 290- | Cook | Chicago | Metrocall | Landline |
| (312) 291- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 293- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 294- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 296- | Cook | Chicago | Nextel Communications, Inc. | Cell Phone |
| (312) 297- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 298- | Cook | Chicago | Sprint Communications Compa... | Landline |
| (312) 299- | Cook | Chicago | Arch Wireless Holdings, Inc. | Cell Phone |
| (312) 300- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 301- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 302- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 303- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 304- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 305- | Cook | Chicago | Cellco Partnership Dba Veri... | Cell Phone |
| (312) 306- | Cook | Chicago | Ameritech Illinois | Landline |
| (312) 307- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 308- | Cook | Schaumburg | Ameritech Illinois | Landline |
| (312) 310- | Cook | Chicago | Cellco Partnership Dba Veri... | Cell Phone |
| (312) 312- | Cook | Chicago | Unknown | Landline |
| (312) 314- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
| (312) 315- | Cook | Chicago | New Cingular Wireless Pcs, ... | Cell Phone |
