Everything You Should Know About Illinois Area Codes

Trying to understand which area code to use for your business in Illinois? 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, grasping the phone number structure in Illinois is essential for seamless contact and verification.

How Illinois Phone Codes Work

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

Structured by the NANP, 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 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 – Overlay for 312 and 773
• 847 – Northern suburbs including Evanston
• 224 – Overlay for 847
• 630 – Western suburbs
• 331 – Overlay for 630
• 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.

Find Area Codes for Illinois Cities

You can use online 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

Entrepreneurs and service providers rely on local numbers to appear local and trustworthy in customers’ eyes.

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

Looking to get started? Check out Bling’s virtual number options today.

Illinois Area Code Overlays

Illinois uses overlay area codes to handle the increasing demand for phone numbers.

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.

This flexibility helps businesses here scale, reach target markets, and streamline support.

Buying an Illinois Local Business Number

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

For example, Illinois phone number for business instantly connects you with your target region.

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

Frequently Asked Questions About Illinois Area Codes