Complete Guide to Illinois Phone 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 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

The area code system in Illinois segments regions for organized call routing, 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.

Current List of Illinois Area Codes

Find all the active codes below showing city coverage and overlays:

• 217 – Covers Springfield, Champaign, and surrounding areas
• 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 – Northern suburbs including Evanston
• 224 – Overlay for 847
• 630 – Covers DuPage County, Naperville, Wheaton
• 331 – Overlay for 630
• 708 – Southwest Chicago suburbs
• 815 – Rockford and northern IL
• 779 – Same coverage region
• 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 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 establish trust, improve response rates, and localize presence.

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

Looking to get started? Check out Bling’s local number services today.

Overlay Area Codes in Illinois

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)

Users must now dial 10 digits, even for local calls, due to overlays.

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

Impact of VoIP on Illinois Numbers

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

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

Buying an Illinois Local Business Number

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

You can register a business phone number with get Illinois area code 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