Area Code 312 is located in the state of Illinois.
The Illinois`s major city is Chicago
The state of Illinois is in Central timezone.
More important cities in Illinois:
Chicago, IL;
Prefixes within the 312 Area Code what we have in our database.
| Prefix | Primary City | County | Usage |
| (312) 201 | Chicago, IL | Cook | Landline |
| (312) 202 | Chicago, IL | Cook | Landline |
| (312) 203 | Chicago, IL | Cook | Cell Number |
| (312) 204 | Chicago, IL | Cook | Landline |
| (312) 205 | Chicago, IL | Cook | Landline |
| (312) 206 | Chicago, IL | Cook | Cell Number |
| (312) 207 | Chicago, IL | Cook | Landline |
| (312) 208 | Chicago, IL | Cook | Cell Number |
| (312) 209 | Northbrook, IL | Cook | Cell Number |
| (312) 210 | Chicago, IL | Cook | Landline |
| (312) 212 | Chicago, IL | Cook | Landline |
| (312) 213 | Chicago, IL | Cook | Cell Number |
| (312) 214 | Chicago, IL | Cook | Landline |
| (312) 215 | Wheeling, IL | Cook | Cell Number |
| (312) 216 | Not filled | Cook | Cell Number |
| (312) 217 | Chicago, IL | Cook | Cell Number |
| (312) 218 | Chicago, IL | Cook | Cell Number |
| (312) 220 | Chicago, IL | Cook | Landline |
| (312) 221 | Not filled | Cook | Cell Number |
| (312) 222 | Chicago, IL | Cook | Landline |
| (312) 223 | Chicago, IL | Cook | Landline |
| (312) 224 | Chicago, IL | Cook | Landline |
| (312) 225 | Chicago, IL | Cook | Landline |
| (312) 226 | Chicago, IL | Cook | Landline |
| (312) 227 | Chicago, IL | Not filled | Unknown |
| (312) 228 | Chicago, IL | Cook | Landline |
| (312) 229 | Chicago, IL | Cook | Landline |
| (312) 230 | Chicago, IL | Cook | Landline |
| (312) 231 | Roselle, IL | Du Page | Cell Number |
| (312) 232 | Chicago, IL | Cook | Cell Number |
| (312) 233 | Chicago, IL | Cook | Landline |
| (312) 234 | Chicago, IL | Cook | Landline |
| (312) 235 | Chicago, IL | Cook | Landline |
| (312) 236 | Chicago, IL | Cook | Landline |
| (312) 237 | Chicago, IL | Cook | Cell Number |
| (312) 238 | Chicago, IL | Cook | Landline |
| (312) 239 | Chicago, IL | Cook | Landline |
| (312) 240 | Chicago, IL | Cook | Landline |
| (312) 241 | Not filled | Cook | Cell Number |
| (312) 242 | Chicago, IL | Cook | Landline |
| (312) 243 | Chicago, IL | Cook | Landline |
| (312) 244 | Chicago, IL | Cook | Landline |
| (312) 245 | Chicago, IL | Cook | Landline |
| (312) 246 | Wheeling, IL | Cook | Cell Number |
| (312) 247 | Chicago, IL | Cook | Landline |
| (312) 249 | Chicago, IL | Cook | Cell Number |
| (312) 250 | Chicago, IL | Cook | Cell Number |
| (312) 251 | Chicago, IL | Cook | Landline |
| (312) 252 | Chicago, IL | Cook | Landline |
| (312) 253 | Chicago, IL | Cook | Landline |
| (312) 254 | Chicago, IL | Cook | Landline |
| (312) 255 | Chicago, IL | Cook | Landline |
| (312) 256 | Chicago, IL | Cook | Landline |
| (312) 258 | Chicago, IL | Cook | Landline |
| (312) 259 | Chicago, IL | Cook | Cell Number |
| (312) 260 | Chicago, IL | Cook | Landline |
| (312) 261 | Chicago, IL | Cook | Landline |
| (312) 262 | Chicago, IL | Cook | Landline |
| (312) 263 | Chicago, IL | Cook | Landline |
| (312) 264 | Chicago, IL | Cook | Landline |
| (312) 265 | Chicago, IL | Cook | Landline |
| (312) 266 | Chicago, IL | Cook | Landline |
| (312) 267 | Chicago, IL | Cook | Landline |
| (312) 268 | Chicago, IL | Cook | Landline |
| (312) 269 | Chicago, IL | Cook | Landline |
| (312) 271 | Chicago, IL | Cook | Cell Number |
| (312) 272 | Chicago, IL | Cook | Cell Number |
| (312) 274 | Chicago, IL | Cook | Landline |
| (312) 275 | Chicago, IL | Cook | Landline |
| (312) 276 | Chicago, IL | Cook | Landline |
| (312) 277 | Chicago, IL | Cook | Landline |
| (312) 278 | Chicago, IL | Cook | Landline |
| (312) 279 | Chicago, IL | Cook | Landline |
| (312) 280 | Chicago, IL | Cook | Landline |
| (312) 281 | Chicago, IL | Cook | Landline |
| (312) 282 | Chicago, IL | Cook | Cell Number |
| (312) 283 | Chicago, IL | Cook | Landline |
| (312) 284 | Chicago, IL | Cook | Landline |
| (312) 285 | Chicago, IL | Cook | Cell Number |
| (312) 286 | Chicago, IL | Cook | Cell Number |
| (312) 287 | Chicago, IL | Cook | Cell Number |
| (312) 288 | Chicago, IL | Cook | Landline |
| (312) 289 | Chicago, IL | Cook | Cell Number |
| (312) 290 | Chicago, IL | Cook | Cell Number |
| (312) 291 | Chicago, IL | Cook | Landline |
| (312) 293 | Chicago, IL | Cook | Landline |
| (312) 294 | Chicago, IL | Cook | Landline |
| (312) 295 | La Grange Park, IL | Cook | Cell Number |
| (312) 296 | Chicago, IL | Cook | Cell Number |
| (312) 297 | Chicago, IL | Cook | Landline |
| (312) 298 | Chicago, IL | Cook | Landline |
| (312) 299 | Chicago, IL | Cook | Cell Number |
| (312) 300 | Not filled | Cook | Landline |
| (312) 301 | Hinsdale, IL | Du Page | Cell Number |
| (312) 302 | Chicago, IL | Cook | Landline |
| (312) 303 | Wheeling, IL | Cook | Cell Number |
| (312) 304 | Hinsdale, IL | Du Page | Cell Number |
| (312) 305 | Northbrook, IL | Cook | Cell Number |
| (312) 306 | Chicago, IL | Cook | Landline |
| (312) 307 | Chicago, IL | Cook | Cell Number |
We have 695 Prefixes in our database.