The 773 area code covers Chicago in Illinois.
Area code 773 is in Illinois, on Central Time. In the 773 area, phone numbers are given out in Cook County. It has been in service since October 12, 1996. 872 covers the same area, so two neighbours can have different area codes.
- Where
- Cook County, Illinois
- Time zone
- Central Time
- In service since
- October 12, 1996
- Shares its area with
- 872 (since 2009)
- Prefixes in use
- 786
- How to dial
- Local calls need 1, then the area code, then the number: 1-773-555-0142.
Find out who called you from a 773 number.
Enter the full 10-digit number to see who it is listed to and the city and state on the listing. It is the same free check as our who called me lookup. To see only the caller ID name on the number, use our free CNAM lookup. To see whether it is a mobile, a landline or a VoIP line, use our free VoIP checker. To see which carrier a (773) number is on today, use our free carrier lookup.
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Chicago holds every phone prefix in area code 773.
A prefix is the three digits after the area code, and NANPA assigns each one to a town. Counting the 786 prefixes in use shows where 773 numbers are actually given out.
- Chicago786 prefixes, 100%
Illinois Bell (AT&T) holds the most phone number prefixes in area code 773: 257 of 786.
NANPA, which runs the North American numbering plan, assigns each prefix (the three digits after the area code) to one carrier. Here is how the 786 prefixes in use in 773 divide between carriers; holders this page does not name are grouped as other carriers.
| Carrier | Prefixes | Share |
|---|---|---|
| Illinois Bell (AT&T)AT&T's landline company | 257 | 33% |
| T-MobileMobile network | 169 | 22% |
| AT&T MobilityMobile network | 84 | 11% |
| Level 3 (Lumen)Lumen's business and wholesale network | 36 | 5% |
| PAETEC (Windstream)Windstream's business phone network | 33 | 4% |
| Teleport (AT&T)AT&T's business phone network | 23 | 3% |
| 14 other carriers | 184 | 23% |
62% of these prefixes are pooled, which means the blocks of 1,000 numbers inside them can belong to other carriers. Any number can also have been moved to another carrier since, so this shows who holds the prefixes, not who serves a given number.
Want the carrier of one exact number? Our free carrier lookup checks it, because numbers move between carriers.
Source: NANPA central office code assignments, October 1, 2026.
773 has covered the same ground since 1996.
1996
773 starts on October 12, 1996, split off from 312.
A 773 number on your screen can still be a scam, because caller ID is easy to fake.
- Let an unknown call go to voicemail. A real caller leaves a message; a robocaller usually does not.
- Look the number up with the box above before you call back, because calling back tells a robocaller your line is live.
- Hang up on anyone who wants gift cards, crypto or a wire transfer, or asks you to read out a code that was just texted to you.
- Report unwanted robocalls at reportfraud.ftc.gov, or paste a suspicious message into our free scam checker.
The area codes closest to 773 are 708, 630 and 847.
This list measures the distance between the centres of each area, across state lines, and shows codes that share one area together.
These are the questions people ask most about area code 773.
Where is area code 773?
773 covers Chicago in Illinois. In the 773 area, phone numbers are given out in Cook County.
What state is area code 773 in?
Illinois. 773 is an Illinois area code on Central Time.
Which phone company owns area code 773?
No single phone company owns 773. NANPA's records show Illinois Bell (AT&T) holds the most 773 prefixes, 257 of 786, followed by T-Mobile and AT&T Mobility. Numbers move between carriers, so check one exact number with a carrier lookup.
What time zone is area code 773 in?
773 is on Central Time.
When did area code 773 start?
773 went into service on October 12, 1996, when it was split off from 312.
Is 773 the same area as 872?
Yes. 872 (since 2009) covers the same ground as 773. Nobody's number changed when it was added; new lines simply get whichever code has numbers left, so two neighbours can have different codes.
How do I dial a 773 number?
Local calls need 1, then the area code, then the number: 1-773-555-0142.
Is 773 a toll-free number?
No. 773 is a regular area code for Chicago in Illinois, not a toll-free one. The toll-free codes in North America are 800, 833, 844, 855, 866, 877 and 888.
What area codes are near 773?
The closest are 708/464 (La Grange, Illinois), 630/331 (Roselle, Illinois), 847/224 (Northbrook, Illinois) and 815/779 (Rockford, Illinois), measured between the centres of each area.
Who called me from a 773 number?
Enter the full 10-digit number in the lookup above. It returns the listed owner where there is a public record, where the number is registered, and whether it is a mobile, a landline or a VoIP line.
Is area code 773 a scam?
773 is a real Illinois area code, so the code itself is not a warning sign. Scam callers fake local-looking numbers on purpose, so judge the call by what the caller asks for, and look the number up before calling back.
Put this lookup on your site: our free area code widget takes two lines of code and shows any US area code's state, time zone and local time.
Source: NANPA, the North American Numbering Plan Administrator: its area code database and prefix assignments, as of October 1, 2026.