Illinois Area Codes Explained

Need to identify or obtain an Illinois-based phone number? This detailed guide 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 crucial for communication.

What Are Area Codes in Illinois?

Area codes in Illinois are three-digit numbers assigned to different regions, supporting phone number management for personal and business use.

Administered by the North American Numbering Plan Administration (NANPA),, Illinois area codes follow a format shared across the U.S. and Canada. For official standards, visit NANPA’s website.

Illinois Area Code List

Here is a breakdown showing city coverage and overlays:

• 217 – Covers Springfield, Champaign, and surrounding areas
• 309 – Western central Illinois
• 312 – Downtown Chicago only
• 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 – 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

Several trusted databases 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

Using Illinois Phone Codes for Business Presence

Companies looking to reach customers in Illinois often opt for local numbers to establish trust, improve response rates, and localize presence.

With services like Bling Cloud, businesses can instantly activate virtual numbers for any Illinois list of area codes in Illinois region.

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

Overlay Area Codes in Illinois

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

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)

Each overlay covers the same geographic region as the original area code.

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

Impact of VoIP on Illinois Numbers

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

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

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

Explore VoIP number options for Illinois today.

FAQ – Illinois Phone Codes