Illinois Area Codes Explained

Need to identify or obtain an Illinois-based phone number? We’ll break it all down for you in this comprehensive post covers all major and minor Illinois area codes

Whether you're a resident, traveler, or business owner, understanding Illinois’ telephone code system is essential for seamless contact and verification.

What Are Area Codes in Illinois?

Area codes in Illinois are three-digit numbers assigned to different regions, allowing calls to be directed accurately.

Supervised by NANPA and the FCC,, the state of Illinois adheres to NANP’s numbering scheme. For official standards, visit NANPA’s website.

Active Area Codes in IL

Find all the active codes below of Illinois area codes organized by coverage area:

• 217 – Covers Springfield, Champaign, and surrounding areas
• 309 – Western central Illinois
• 312 – Downtown Chicago only
• 773 – Rest of Chicago outside downtown
• 872 – Covers greater Chicago metro
• 847 – North Chicago suburbs
• 224 – Overlay for 847
• 630 – Covers DuPage County, Naperville, Wheaton
• 331 – Overlay for 630
• 708 – Oak Lawn, Cicero
• 815 – Rockford and northern IL
• 779 – Overlay for 815
• 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 boost call pick-up rates and brand visibility.

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 cloud phone platforms 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

Here’s how the area codes are split by region in Illinois:

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

Impact of VoIP on Illinois Numbers

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 area code with VoIP solutions.

How to Get a Local Number in Illinois

Getting a business phone number with an Illinois area code enhances regional credibility.

You can register a business phone number with any Illinois code through platforms like Bling.

You don’t need to be in Illinois physically—virtual systems handle routing through VoIP or PBX networks.

FAQ – Illinois Phone Codes