312 area code: location, overlays and numbers
In Chicago, Illinois, area code 312 has served as a US telephone area code since 1947, and it shares an overlay with 872.
- Location
- Chicago, Illinois
- Serving since
- 1947
- The time zone
- Central time zone
- Overlay
- 872
- Calls inside the area
- Dial 1, then the 10-digit number
- The rate centres
- 1
- Expected exhaust
- 2049
- Country calling prefix
- +1 (United States)
Figures come from NANPA public reports: the area code report and the rate-centre report, file dated 11/01/2026. The exhaust year comes from the NANPA projections file 2026-1 (April 2026). We are not an official NANPA site.
Pick up a 312 number
You can get a 312 number in two ways. When you sign up, a provider gives you a new number with its plan, picked from the numbers it already holds in the code. Numbers a seller already holds, often with a pattern, are listed for a one-time price, and later you move that number over to a provider.
Providers ranked by first-year cost
| Provider | Cheapest plan | First year | Link |
|---|---|---|---|
 Free app | Basic (Just for me), free | $0 | Open Google Voice |
 Free app | Free plan, free | $0 | Open TextNow |
 Developer API | Pay-as-you-go local number, $1.15 a month | $13.80 | Open Twilio |
 Second-number app | Standard, $3.99 a month billed yearly | $47.99 | Open Burner |
 Toll-free specialist | Solo, $6.99 a month billed yearly | $84 | Open UniTel Voice |
 Second-number app | Deluxe (local number), $6.99 a month billed yearly | $102.88 | Open GoDaddy Conversations (formerly Smartline) |
Sellers that list local numbers
| Seller | What it sells | Listed price | Monthly fee | Link |
|---|---|---|---|---|
 Marketplace | Local numbers | From $9 one-time | None stated | Search at Exclusive Digits |
 Marketplace | Local and toll-free | From $9.95 one-time | $2.99 a month | Search at NumberBarn |
 Number broker | Local and toll-free | From $99 one-time | None stated | Search at RingBoost |
 Number broker | Local and toll-free | From $100 one-time | None stated | Search at PhoneNumberExpert |
| 212areacode.comNumber broker | Local numbers | From $150 one-time | None stated | Search at 212areacode.com |
Some sellers and providers may pay us a referral fee. How we earn: referral fees never affect the order, which is based on first-year cost.
Area codes related to this one
One area, one pool of numbers: 872. Any of these codes can give you a new number in this area, so request whichever one you want.
Elsewhere in Illinois: 217, 309, 618, 708, 815, 630, 847, 224, 773, 331, 779, 447, 464, 730 and 861.
City guides include Chicago area codes.
312 area code questions
Where does area code 312 serve?
Chicago, Illinois is served by 312, around metro Chicago-Naperville-Elgin, IL-IN.
Which country code does a 312 number use?
+1. The North American Numbering Plan covers 312, so callers abroad dial +1 312 plus the 7-digit number.
What time is it in the 312 area code?
312 follows Central time.
Who calls using a 312 number?
These numbers are used by homes, mobiles and local businesses, and also by callers who fake a local number. The 312 number you see on your screen points to where it was assigned, not to who is calling.
Is a 312 number toll-free?
No. 312 is a local area code, so calls to it are charged the same way as any other US call. US toll-free prefixes: 833, 844, 855, 866, 877, 888 and 800.
Why do people want 312 numbers?
Sellers ask more for 312 numbers because the code was among the 86 original ones from 1947 and the first assigned to a big city. Our scoring guide gives it the highest area-code score.