Area code 312
Illinois · Chicago (Loop)
- Area code
- 312
- Country
- United States
- Region
- Illinois
- Major cities
- Chicago (Loop)
- Time zone
- America/Chicago
- Note
- Central Chicago area code.
This is a domestic area code inside United States. It is not the international calling code.
Frequently asked questions
Which cities use area code 312?
Area code 312 serves Illinois in United States, including Chicago (Loop).
What region does area code 312 cover?
Area code 312 covers Illinois. Area codes route calls to a specific city or region within a country's national telephone network.
What is the difference between an area code and a calling code?
A calling code routes a call across borders to a national network, while an area code routes it to a city or region inside that network. For a United States number, the country calling code is the international prefix and 312 is the domestic area code.
What time zone is area code 312 in?
Area code 312 is in the IANA time zone America/Chicago.
Is area code 312 the international calling code?
No. 312 is a domestic area code inside United States, not the international calling code. To call this region from abroad, you dial the country's calling code first, then 312 and the local number.