Telephone Area 312. Page 1.

In the United States, telephone numbers are divided into a country code (+1), an area code (or prefix), which is three digits long, and a subscriber number (seven digits). These are just a few examples, and there are over 300 area codes in the United States. Each code can cover both large cities and less populated areas depending on population density and telephone network distribution.

The table below shows the main major cities and telecom operators.

If you notice any errors of any community’s location on the map, please report it via the feedback form.

Phone numbers +1-312-YYY-YYYY