Area Code 312
Area code 312 is associated with Illinois. It connects to 18 ZIP codes across 1 cities, with an estimated combined population of 212,991.
Area details
- Area code
- 312
- States covered
- Illinois
- States count
- 1
- ZIP codes
- 18
- Cities
- 1
- Population
- 212,991
Related ZIP codes
Open ZIP state pageAbout area code 312
Area code 312 is a useful lookup entry for Illinois. It helps connect phone-number geography with ZIP code coverage, city clusters, and state-level browsing. Use the related ZIP cards above to move deeper into the postal data for this region.
If you are browsing by state, you can continue with Illinois lookup pages for ZIP codes and area codes.