Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

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zipcodes.pro — AREA-CODE/773

773 area code

Area code 773 is in Illinois. It covers Chicago and Burnham: 84 ZIP codes in Cook County. Local time there is , Central Time. In service since 1996; 872 (2009) overlays it, so a number from there can have either code.

Time zone
Central
Largest city
Chicago
Overlays
872
In service since
1996
Rate centres
11
Prefixes assigned
786 (7,860,000 numbers)

Who calls from a 773 number

NANPA records the carrier each block of 773 numbers is assigned to. Of the 7.7 million 773 numbers assigned, 45% are with mobile carriers (T-Mobile, AT&T Mobility and Verizon Wireless); 30% with local phone companies (AT&T); 23% with cable, internet-calling, business and other carriers (Onvoy and Bandwidth); 3% with paging companies.

That is who the numbers were assigned to: people keep their number when they change carrier, so any one number may have moved since.

Carriers holding the most 773 numbers
CarrierKindShare
AT&TLandline30%
T-MobileMobile26%
AT&T MobilityMobile11%
Verizon WirelessMobile8%
OnvoyCable, VoIP, other5%
BandwidthCable, VoIP, other4%

An area code says where a number was issued, not where the caller is: people keep their numbers when they move, and caller ID can be set to show any number, which the FCC calls spoofing. If a call you did not expect asks for money or personal details, the FCC advises hanging up and calling the company back on a number you look up yourself. Unwanted calls can be reported to the FTC at ReportFraud.ftc.gov.

Places in area code 773

The 1 place with a telephone rate centre of its own using 773, largest first. Each links to its ZIP codes.

Places in area code 773
PlaceZIP codesPopulation
Chicago, IL 84 2,711,226

Nearby places using 773

These places have no rate centre of their own in NANPA's records; the nearest one uses 773. Near an area-code boundary that can be wrong for part of a town.

ZIP codes in area code 773

84 ZIP codes in 1 town, by the town each is mailed to, largest first. Each links to its own page.

Where 773 numbers are issued

NANPA's rate centres with the most 773 prefixes (each prefix is 10,000 numbers), under NANPA's own abbreviated names.

Rate centres using area code 773
Rate centrePlacePrefixes
CHICGOZN03 Chicago 170
CHICGOZN01 Chicago 124
CHICGOZN02 Chicago 79
CHICGOZN07 Chicago 78
CHICGOZN04 Chicago 75
CHICGOZN10 Chicago 72

Counties

The counties of its ZIP codes, most residents first, with how many of its ZIP codes each has.

Which code covers where you are now? What area code am I in? answers from your location.

Questions about area code 773

Where is area code 773?

Area code 773 is in Illinois. It covers Chicago and Burnham: 84 ZIP codes in Cook County.

What ZIP codes are in area code 773?

84 ZIP codes, by the town each is mailed to: Chicago (84, 60601 to 60701). The full list is on this page.

What time zone is area code 773 in?

Central time.

Is a 773 number a mobile or a landline?

It can be either. 45% of 773 numbers are assigned to mobile carriers and 30% to local phone companies (NANPA, 2026-10-10); the rest are with cable, internet-calling, business and paging carriers. A number keeps its area code when it moves to another carrier.

What area codes overlay 773?

872. They cover the same area as 773, so a new number there can be given any of them.

Does a 773 number mean the caller is in Illinois?

Not necessarily. An area code says where the number was first issued. People keep their numbers when they move or switch carriers, and calling software can show any number, so a 773 call can come from anywhere.

Other area codes in Illinois

All 17 Illinois area codes, by area, with the cities each covers

Source: NANPA NPA database, central office code and thousands-block assignments, 2026-10-10. Places are matched to NANPA's rate centres by name; see sources.

Cite this page

zipcodes.pro. “Area code 773.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/area-code/773

Underlying data is public domain or openly licensed — sources, vintages and licences.