Area codes are a crucial part of the North American Numbering Plan (NANP). They help direct phone calls to the correct geographic area.
This article is all about area code 312.
Area code 312 is a historically important area code because it serves a vital part of Chicago, Illinois. In fact, it was the original area code for the entire city. Now, it serves the Chicago Loop and nearby neighborhoods.
Read on to learn more about the location of area code 312, its history, how it’s used today, and how you can get a 312 number.
Where is area code 312?
The main area covered by the 312 area code is downtown Chicago, including the area known as The Loop. The Loop is Chicago’s central business district.
It’s important to know that area code 312 doesn’t cover the entire city of Chicago. It’s surrounded by other area codes, including 773, 847/224, 708, 630, and 331.
According to recent estimates, over 2.9 million people live in the 312 area, which is about 23% of the population of Illinois.
Cook County, Illinois, is the most populous county in the 312 area code, with over 5 million residents. Chicago itself is the most populous city in the 312 area code, with nearly 2.7 million residents.
A Quick History of Chicago’s 312 Area Code
Area code 312 is one of the original 86 area codes created in North America in 1947. Back then, it covered the entire Chicago metropolitan area.
Originally, area codes could only have a 0 or 1 as the middle digit. A “0” meant the entire state, while a “1” indicated a portion of the state.
In 1996, the area code split, and some phone numbers were assigned to area code 773.
Then, in 2009, area code 872 was created as an overlay, meaning it served the same geographic area as 312 and 773.
Here’s a fun fact: back in the day of rotary phones, the number of “pulses” required to dial a number mattered. Area code 312 only needed 6 pulses, a big advantage for a densely populated area. In fact, area codes created 5 years before or after 312 averaged 14.1 pulses. Today’s active area codes average 16.3 pulses!
Time Zone and Calling Area Code 312
Area code 312 follows Central Time, which is also known as America/Chicago time.
To call a number in area code 312, dial 1 + 312 + the seven-digit phone number. Depending on where you are, you may need to dial the area code even for local calls.
Telephone Carriers and Prefixes in Area Code 312
The 312 area code is served by several telephone carriers, both landline and wireless. Here’s a breakdown of the largest carriers and their prefix usage:
Landline Carriers
- Ameritech: 41% of prefixes
- RCN Telecom Services: 9% of prefixes
- Broadwing Communications: 3% of prefixes
- Other: remaining prefixes
Wireless Carriers
- Cingular: 9% of prefixes
- Verizon: 6% of prefixes
- USA Mobility: 5% of prefixes
- Sprint: 3% of prefixes
- Other: remaining prefixes
Prefix Usage
Nearly all (99%) of the prefixes within the 312 area code have been assigned to a telecommunications company.
Of those assigned prefixes, about two-thirds (66%) are used by landlines, while the remaining third (34%) are used by wireless carriers.
Getting a 312 area code phone number for your business
Even if your business isn’t physically located in Chicago, you can still get a 312 area code phone number.
Establishing a local presence
Having a 312 area code phone number can give your business a virtual presence in the city, which can enhance your local advertising and marketing efforts. It can also boost your cold calling campaign results.
How to get a 312 number
Many Voice over Internet Protocol (VoIP) services, such as Ringover, offer 312 numbers. The great thing is that you don’t need to have a physical address in Chicago to buy one. You can quickly and easily set one up through one of these services.
Practical applications
You can use the number as a direct phone line, a customer service number, or for sales. Many VoIP services also offer features like call forwarding, call recording, and interactive voice response (IVR).
Frequently Asked Questions
Why is Chicago called the 312?
Chicago is nicknamed “The 312” because 312 is its original and most well-known area code. When area codes were first introduced in 1947, 312 was assigned to the city’s central area. It’s become a symbol of Chicago pride, representing the city’s identity and culture.
Where do you live if your number starts with 312?
If your phone number starts with 312, you most likely live in downtown Chicago or its immediate surrounding neighborhoods. As the city grew, additional area codes were introduced to serve the broader metropolitan area, but 312 remains a core identifier for central Chicago.
What area is 312 in a phone number?
The area code 312 in a phone number covers the heart of Chicago, Illinois. It includes areas such as the Loop, Near North Side, Near South Side, and Near West Side. These are some of the city’s most densely populated and commercially significant areas.
What state code is 312 in the US?
It’s important to clarify that “state code” isn’t the correct term. 312 is an area code, not a state code. The area code 312 is exclusively located within the state of Illinois, specifically covering the central portion of the city of Chicago.
The Bottom Line
Area code 312 is one of the original area codes, and it’s still used today in downtown Chicago and a few surrounding neighborhoods.
More than just a set of digits, 312 is a symbol of Chicago, and for businesses, having a 312 area code can boost your reputation and signal your connection to the heart of the Windy City.