Everything You Should Know About Illinois Area Codes

Are you wondering what area code corresponds to your Illinois city? This detailed guide includes everything from historical area code changes to VoIP business solutions

No matter if you’re launching a business or tracing a call, grasping the phone number structure in Illinois is crucial for communication.

Understanding Illinois Area Codes

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

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

Active Area Codes in IL

Here is a breakdown of Illinois area codes organized by coverage area:

• 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 – Overlay for 312 and 773
• 847 – Northern suburbs including Evanston
• 224 – Overlay for 847
• 630 – Covers DuPage County, Naperville, Wheaton
• 331 – Used in the same region
• 708 – Southwest Chicago suburbs
• 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.

Illinois Area Code Search Tools

Several trusted databases 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.

Modern business platforms make it simple website to buy or assign IL-based numbers.

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

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

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.

Want to learn more? Visit VoIP area code systems in IL for powerful options.

Buying an Illinois Local Business Number

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

For example, get an Illinois-based number 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