Illinois Area Codes Explained

Are you wondering what area code corresponds to your Illinois city? We’ll break it all down for you in this comprehensive post includes everything from historical area code changes to VoIP business solutions

Whether you're a resident, traveler, or business owner, grasping the phone number structure in Illinois is essential for seamless contact and verification.

Understanding Illinois Area Codes

Area codes in Illinois are three-digit numbers assigned to different regions, helping manage number allocation across cities.

Administered by the North American Numbering Plan Administration (NANPA),, Illinois codes align with the NANP guidelines used across North America. For official standards, visit NANPA’s website.

Illinois Area Code List

Below is a current list showing city coverage and overlays:

• 217 – Central Illinois including Springfield
• 309 – Western central Illinois
• 312 – Downtown Chicago only
• 773 – Rest of Chicago outside downtown
• 872 – Covers greater Chicago metro
• 847 – Northern suburbs including Evanston
• 224 – Also covers northern suburbs
• 630 – Western suburbs
• 331 – Overlay for 630
• 708 – Southwest Chicago suburbs
• 815 – Rockford and northern IL
• 779 – Same coverage region
• 464 – Newest overlay for Chicago

To learn more about official overlays and numbering plans, visit the FCC Area Code Resources.

Illinois Area Code Search Tools

You can use online tools that help you identify the area code for a city or trace a phone call.

1. TrueCaller – Reverse lookup and spam detection
2. Whitepages – Detailed contact search and verification
3. Nomorobo – Great for spam and robocall filtering
4. YouTube: Illinois Area Codes Explained – Helpful visual resource
5. Wikipedia List – See historical and current Illinois codes

Why Businesses Choose Local Illinois Numbers

Businesses operating in or targeting Illinois use local area codes to appear local and trustworthy in customers’ eyes.

Using VoIP and virtual phone systems, getting a number with an Illinois area code is now easy and affordable.

If you're setting up a professional phone system with a local presence, explore business phone systems from Bling.

Overlay Area Codes in Illinois

Many IL area codes now have overlays due to high population and business growth.

These are the current overlays used in Illinois:

• 872 – Overlays 312 and 773 (Chicago)
• 464 – Newest overlay for 708 (Chicago suburbs)
• 224 – Overlays 847 (Northern suburbs)
• 331 – Overlays 630 (Western suburbs)
• 779 – Overlays 815 (Northern Illinois)

Users must now dial 10 digits, even for local calls, due to overlays.

Regional Breakdown: Northern, Central, and Southern Illinois Area Codes

Illinois is divided into three primary telephone regions: North, Central, and South.

Northern Illinois

• 312, 773, 872 – Chicago metro|Downtown and metro Chicago
• 847, 224 – Evanston, Waukegan, North Shore|Northern suburbs
• 630, 331 – Naperville, Wheaton, Oak Brook|Western suburbs
• 708, 464 – Cicero, Oak Lawn, South suburbs
• 815, 779 – Rockford, Joliet, Kankakee

Central Illinois

• 217 – Springfield, Urbana, Decatur
• 309 – Peoria, Bloomington, Galesburg

Southern Illinois

• 618 – East St. Louis, Carbondale, Belleville

How VoIP Is Changing Illinois Phone Systems

With the rise of cloud calling, VoIP is becoming the preferred method for phone communication in Illinois.

Whether you're in downtown Chicago or remote southern Illinois, you can now get a local more info area code with VoIP solutions.

How to Get a Local Number in Illinois

It also helps with branding, geo-targeting, and customer service.

For example, Illinois business line instantly connects you with your target region.

It’s also scalable for multiple team members and departments.

Illinois Area Code: Common Questions Answered