Illinois Area Codes Explained

Trying to understand which area code to use for your business in Illinois? You’ve come to the right place—this blog dives into lookup tools, city-based breakdowns, and more.

Whether you're a resident, traveler, or business owner, grasping the phone number structure in Illinois is crucial for communication.

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,, Illinois codes align with the NANP guidelines used across North America. For official standards, visit NANPA’s website.

Active Area Codes in IL

Below is a current list showing city coverage and overlays:

• 217 – Central Illinois including Springfield
• 309 – Peoria, Bloomington, and western parts of IL
• 312 – Central Chicago zone
• 773 – Northwest and South Side of Chicago
• 872 – Covers greater Chicago metro
• 847 – North Chicago suburbs
• 224 – Also covers northern suburbs
• 630 – Western suburbs
• 331 – Used in the same region
• 708 – Southwest Chicago suburbs
• 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.

Find Area Codes for Illinois Cities

There are many reliable lookup tools to discover which city an area code belongs to.

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

Companies looking to reach customers in Illinois often opt for local numbers to boost call pick-up rates and brand visibility.

With services like Bling Cloud, businesses can instantly activate virtual numbers for any Illinois region.

Looking to get started? Check out Bling’s virtual phone numbers today.

Overlay Area Codes in Illinois

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

Here are the main overlays:

• 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.

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

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 new Chicago area code like Bling.

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

Frequently Asked Questions About Illinois Area Codes