Where Is 312 Area Code?
Cities in 312 Area Code
Counties in 312 Area Code
Prefix Codes for Area Code 312
- (312) 201
- (312) 202
- (312) 203
- (312) 204
- (312) 205
- (312) 206
- (312) 207
- (312) 208
- (312) 209
- (312) 212
- (312) 213
- (312) 214
- (312) 215
- (312) 216
- (312) 217
- (312) 218
- (312) 219
- (312) 220
- (312) 221
- (312) 222
- (312) 223
- (312) 224
- (312) 225
- (312) 226
- (312) 227
- (312) 228
- (312) 229
- (312) 230
- (312) 231
- (312) 232
- (312) 233
- (312) 234
- (312) 235
- (312) 236
- (312) 237
- (312) 238
- (312) 239
- (312) 240
- (312) 241
- (312) 242
Illinois Area Codes