Quick answer: The 773 area code covers Chicago's neighborhoods outside the downtown Loop — Pilsen, Logan Square, Hyde Park, Rogers Park, the South Side, and most of the city's residential map. The downtown Loop and innermost core use 312 instead. 773 was carved off from 312 on October 12, 1996, and the citywide 872 overlay has joined both codes since November 7, 2009 — so 10-digit dialing is mandatory across Chicago. The region runs on Central Time and falls mostly within Cook County.
773 area code: Chicago beyond the Loop
Here's something most Chicagoans know instinctively: 312 is downtown, and 773 is everywhere else. The two codes split the same city — one for the central business district, one for the neighborhoods where most people actually live.
If you've got a 773 number, you're tied to the real, residential Chicago: Pilsen, Logan Square, Hyde Park, Rogers Park, the South Side, the far North Side. That distinction is the whole story of this code.
My Country Mobile (MCM) provisions local numbers nationwide, so we'll cover the practical side too — what 773 covers, how the 872 overlay works, dialing rules, and how to get a Chicago number from anywhere.
How 773 splits Chicago with 312
Originally, all of Chicago used 312. As cell phones and pagers exploded in the 1990s, the city ran out of numbers and needed a second code.
The solution was geographic. The downtown core kept 312; everything outside it became 773.
What 773 actually covers
The 773 area code wraps around Chicago's neighborhoods — the residential and outer-city areas beyond the Loop and the innermost downtown blocks.
The retained 312 zone was drawn roughly along North Avenue, Western Avenue, and 35th Street. Step outside that box and you're in 773 territory.
The counties involved
Coverage falls primarily within Cook County, the most populous county in Illinois, with a small portion touching neighboring DuPage County.
Time zone
Chicago runs on Central Time — UTC-6 during standard time and UTC-5 during Daylight Saving Time, observed March through November.
A quick history
Chicago's original code was 312. In 1989, the suburbs were split off as 708, leaving the city itself with 312.
By the mid-1990s, even city-only 312 wasn't enough. On October 12, 1996, the neighborhoods became 773, and permissive 312 dialing ended in January 1997.
Why the split mattered
Keeping 312 for downtown preserved its prestige for businesses, while 773 absorbed the bulk of the population. Nearly thirty years later, that identity has stuck.
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The 872 overlay and 10-digit dialing
Chicago eventually ran low on numbers again. Rather than split the city a third time, regulators added an overlay.
What the 872 overlay is
Area code 872 went into service on November 7, 2009. It overlays both 312 and 773 — meaning 872 numbers can be issued anywhere in the city, sitting on top of the existing codes.
Why you dial 10 digits
With multiple codes covering the same streets, the area code became a mandatory part of every call. All local calls in Chicago require 10-digit dialing — area code plus the seven-digit number.
Opening a Chicago location or adding a line? MCM lets you provision a local 773 number in minutes — virtual, no contract — so you can pick the code before issuing 872 territory eats into supply.
How to dial a 773 number
The format depends on where you're calling from. Local calls inside the Chicago overlay — to a 312, 773, or 872 number — require the full 10 digits, area code included, even when you're calling a neighbour.
Long-distance calls from outside the city add a 1 prefix. International callers dial their exit code (often 00 from most of Europe, 011 from the US, 0011 from Australia), then 1 for the US country code, then the full 10-digit number.
The single rule to remember: never use 7-digit dialing inside Chicago. With three codes sharing the same map, the network needs the area code on every call to route it correctly.
What a 773 number says about a business
Numbers signal identity. In Chicago, the code you carry tells customers something specific about you.
Neighborhood credibility
A 773 number reads as authentically local — rooted in the neighborhoods rather than a corporate downtown address. For community-facing businesses, that's an asset.
Higher answer rates
People answer local numbers more readily than unfamiliar ones. A recognizable Chicago code lifts pickup rates on outbound calls.
Citywide reach
Because 773 spans most of Chicago's residential map, a single number connects you with customers across dozens of neighborhoods.
Getting a 773 number from anywhere
You don't need a physical office in Chicago to hold a Chicago number. Virtual numbers make that presence portable.
How virtual numbers work
A virtual 773 number lives in the cloud and forwards calls to any device — a mobile, a softphone, or an existing business line. Customers see Chicago; your team can be anywhere.
Features to look for
When comparing providers, check for call forwarding, voicemail-to-email, an auto-attendant, call recording, and SMS support. Those features turn a number into a working business line.
MCM provisions local numbers across 190+ countries and serves 17,500+ businesses, so a Chicago setup is quick whether you're a local startup or expanding into the market.
Watching out for 773 spam calls
Like any busy urban code, 773 attracts spam and spoofing. A few habits keep you protected.
Common warning signs
Be cautious with unexpected calls claiming urgent account issues, prize wins, or government demands. Legitimate organizations rarely demand instant payment by phone.
How to stay safe
Let unknown 773 calls go to voicemail, verify any caller through an official number you look up yourself, and report persistent spam to the FTC. Caller authentication standards like STIR/SHAKEN are cutting spoofed traffic, but caution still helps.
What to do next
The 773 code tells a clear story: it's the Chicago of neighborhoods, not skyscrapers — overlaid by 872, dialed with 10 digits, and still a strong local signal for any business.
If a Chicago presence is on your roadmap, the easiest first step is testing a local number. You can explore virtual phone numbers with MCM and have a 773 line live in about five minutes — no credit card, no contract.
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Frequently asked questions about the 773 area code
Where is the 773 area code located?
In Chicago, Illinois — specifically the city's neighborhoods outside the downtown Loop, which uses 312. Coverage is mostly within Cook County.
What's the difference between 312 and 773?
312 covers Chicago's central business district and innermost neighborhoods. 773 covers the rest of the city — the residential and outer-city areas.
Does the 773 area code have an overlay?
Yes. Area code 872 overlays 773 (and 312), in service since November 7, 2009. New numbers in Chicago may be issued under 872.
Why do I have to dial 10 digits in Chicago?
Because multiple codes cover the same area, the area code is a required part of every call. All local Chicago calls need 10-digit dialing.
What time zone is the 773 area code in?
Central Time — UTC-6 during standard time and UTC-5 during Daylight Saving Time.
When was the 773 area code created?
It went into service on October 12, 1996, when Chicago's neighborhoods were split off from the original 312 code.
Can I get a 773 number if I don't live in Chicago?
Yes. A virtual 773 number from a provider like MCM gives you a Chicago presence with calls forwarded to any device, anywhere.
Get a 773 number for your business
A Chicago presence used to mean leasing space in Pilsen or Logan Square. Now it's a few-minute signup.
My Country Mobile offers 773 virtual numbers with call forwarding, voicemail-to-email, SMS, and AI call transcription. Calls route to any device worldwide, and over 17,500 businesses already trust MCM with their virtual phone presence.
