312 area code: Downtown Chicago, time zone and cities
Area code 312 covers downtown Chicago, including the Loop and the areas right around it. It is roughly bounded by North Avenue, Western Avenue, 35th Street and Lake Michigan. Area code 773 surrounds it.
Quick facts
- Location
- Downtown Chicago, Illinois
- State
- Illinois
- Time zone
- Central TimeLocal time now:
- Overlay
- Yes. 312 shares its area with 872.
- In service since
- 1947, one of the original area codes
Cities and places in area code 312
- Chicago (downtown and the Loop)
Area codes that share or border 312
Same area (overlay)
- 872
Area code 872 overlays both 312 and 773.
Nearby
- 773 IL
Is a call from 312 a scam?
The area code alone says nothing about the caller. It shows where the number was set up. It does not show who is calling or where they are. The FTC says scammers can make any name or number show up on caller ID. This is called spoofing, and it can make a call look local when it comes from anywhere in the world.
Signs of a phone scam, from the FTC:
- The caller says you won a prize, but you have to pay to get it.
- The caller says you will be arrested or fined unless you pay right away. Real law enforcement and federal agencies do not call and threaten you.
- The caller insists you pay by gift card, wire transfer, cryptocurrency or a payment app.
- The caller says they are from a government agency and asks for your Social Security number.
What to do:
- If you get a robocall, hang up. Do not press any number, which could lead to more robocalls.
- Ask your phone carrier what call blocking it offers.
- Report unwanted calls at DoNotCall.gov. If you lost money, report it at ReportFraud.ftc.gov.
How to get a 312 phone number
For an AI agent or a business
Our API lines are real T-Mobile mobile numbers for texts, or for texts and calls over SIP, rented by the month. Add "area_code": "312" to an order to ask for 312 numbers.
The area code is a request and is not guaranteed. Numbers come from our stock and from the carrier, so some can have another area code. If the carrier cannot fill the request within about an hour, we send numbers from other area codes.
Numbers for AI agents and businesses
For your own phone
Our T-Mobile Talk & Text line asks where your number should come from at checkout. Pick Chicago, IL and we ask the carrier for a number there. You can also give your own US address, and we ask for a number local to its ZIP code. The carrier picks the area code, so a 312 number is not guaranteed.
Our Unlimited line has no area code choice.
Questions about area code 312
Where is area code 312?
Area code 312 covers downtown Chicago, including the Loop and the areas right around it. It is roughly bounded by North Avenue, Western Avenue, 35th Street and Lake Michigan. Area code 773 surrounds it.
What time zone is area code 312 in?
Central Time.
Which area codes share 312's area?
872. Area code 872 overlays both 312 and 773.
When did area code 312 start?
In 1947. 312 is one of the original North American area codes.
Is a call from area code 312 a scam?
The area code alone does not make a call a scam. It shows where the number was set up. The FTC says scammers can make any number show up on caller ID. If you get a robocall, hang up without pressing any number, and report unwanted calls at DoNotCall.gov.
How can I get a phone number with area code 312?
For your phone, our T-Mobile Talk & Text line asks for a city at checkout: pick Chicago, IL and we ask the carrier for a number there. For an AI agent or a business, add "area_code": "312" to an API order. Either way the area code is a request and is not guaranteed.
Sources: NANPA area code database, file of November 3, 2026 (state, time zone, overlays, year in service); Wikipedia, "Area code 312", revision of June 14, 2026 (area, places and neighbors); FTC, "Phone Scams" and "How To Block Unwanted Calls" (call advice). Checked November 3, 2026.