🇺🇸 312 area code
Area code 312 covers Chicago and the surrounding area in Illinois. It shares that territory with 872, so the same neighbourhood can have numbers in any of them. Enter a 312 number below for a free check before you call back.
- Location: Chicago, Illinois
- Time zone: Central (UTC−6)
- In service since 1947
Consultar un número
Validez, operador, tipo de línea y región en la primera pasada.
Area code 312 at a glance
Cities in area code 312
- Chicago
Is a 312 call a scam?
An area code tells you where a number was first assigned, not where the caller is. Mobile numbers keep their area code when people move, and internet (VoIP) numbers can be picked in any area code — so a 312 number can be calling from anywhere.
Robocallers exploit that with "neighbor spoofing": showing a 312 number to people in Illinois because a local-looking call is more likely to be answered. If a 312 call claims to be your bank, the IRS or a delivery company, hang up and call the official number yourself.
About area code 312
312 is one of the original North American area codes, created in 1947 when AT&T and the Bell System first divided the continent into numbering plan areas.
It is part of the 312/872 overlay: the codes cover the same area, and a new line there can be given a number in any of them. Two neighbours — or two phones in one household — can have different area codes. That is also why local calls need the full ten digits.
As the region grew, 708, 773 and 872 were carved out of or added to 312.
Preguntas frecuentes
Area code 312 questions
Sources: NANPA NPA database (11/04/2026) and Google libphonenumber. Area codes show where a number was assigned, not where its owner is today.
Where is area code 312?
Area code 312 is in Illinois, United States. It covers Chicago.
What time zone is area code 312?
312 is in the Central (UTC−6) time zone, and observes daylight saving time.
What area codes overlay 312?
872 serves the same area as 312. Numbers in all of them are local to one another.
When did area code 312 start?
312 entered service in 1947.
How do I find out who called me from 312?
Enter the full number in the lookup at the top of this page. The free check confirms whether the number is valid and shows its carrier, line type and region; a full report adds owner and public-web records where they are available.
Why am I getting calls from area code 312?
If you live in or near Illinois, they may be genuinely local — or robocalls spoofing a local-looking number. Unknown 312 callers who will not leave a message are best looked up before you call back.
Got a call from 312?
Run the free check first — validity, carrier, line type and region — and unlock the full report only if you need it.