Everything You Should Know About Illinois Area Codes

Need to identify or obtain an Illinois-based phone number? We’ll break it all down for you in this comprehensive post covers all major and minor Illinois area codes

No matter if you’re launching a business or tracing a call, knowing the dialing system across IL helps with routing calls, marketing, and compliance.

Understanding Illinois Area Codes

Illinois telephone area codes identify specific geographic territories, allowing calls to be directed accurately.

Supervised by NANPA and the FCC,, the state of Illinois adheres to NANP’s numbering scheme. For official standards, visit NANPA’s website.

Illinois Area Code List

Below is a current list 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 – Overlay for 630
• 708 – Oak Lawn, Cicero
• 815 – Spans northern rural regions
• 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

Several trusted databases 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

Why Businesses Choose Local Illinois Numbers

Entrepreneurs and service providers rely on local numbers to establish trust, improve response rates, and localize presence.

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.

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

Voice over IP (VoIP) services have revolutionized how people and businesses use area codes.

Want to learn more? Visit VoIP-powered Illinois business calling for powerful options.

How to Get a Local Number in Illinois

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

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

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

Frequently Asked Questions About Illinois Area Codes