Comprehensive Guide to Illinois Area Codes

Illinois Area Codes Explained

Are you wondering what area code corresponds to your Illinois city? You’ve come to the right place—this blog includes everything from historical area code changes to VoIP business solutions

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

How Illinois Phone Codes Work

Illinois telephone area codes identify specific geographic territories, supporting phone number management for personal and business use.

Supervised by NANPA and the FCC,, Illinois area codes follow a format shared across the U.S. and Canada. For official standards, visit NANPA’s website.

Current List of Illinois Area Codes

Here is a breakdown showing city coverage and overlays:

• 217 – Central Illinois including Springfield
• 309 – Western central Illinois
• 312 – Central Chicago zone
• 773 – Rest of Chicago outside downtown
• 872 – Covers greater Chicago metro
• 847 – Northern suburbs including Evanston
• 224 – Also covers northern suburbs
• 630 – Covers DuPage County, Naperville, Wheaton
• 331 – Used in the same region
• 708 – Southwest Chicago suburbs
• 815 – Rockford and northern IL
• 779 – Same coverage region
• 464 – Launched to support number exhaustion

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

How to Lookup Illinois Area Codes

There are many reliable lookup tools to find an Illinois area code by city or number.

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

Using Illinois Phone Codes for Business Presence

Businesses operating in or targeting Illinois use local area codes to boost call pick-up rates and brand visibility.

Modern business platforms make it simple to buy or assign IL-based numbers.

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

Illinois Area Code Overlays

To prevent exhaustion of available numbers, Illinois area code updates Illinois has implemented overlays in many regions.

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)

Overlay codes don’t replace old ones but coexist in the same region.

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

Phone area codes in Illinois follow regional distributions across the state.

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

VoIP lets you use any area code in Illinois without a physical presence.

Want to learn more? Visit VoIP area code systems in IL for powerful options.

Get a Business Number with an Illinois Area Code

Local numbers are critical for customer trust.

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

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

Frequently Asked Questions About Illinois Area Codes