Illinois Area Codes Explained

Trying to understand which area code to use for your business in Illinois? This detailed guide covers all major and minor Illinois area codes

No matter if you’re launching a business or tracing a call, grasping the phone number structure in Illinois is essential for seamless contact and verification.

How Illinois Phone Codes Work

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

Structured by the NANP, Illinois area codes follow a format shared across the U.S. and Canada. For official standards, visit NANPA’s website.

Active Area Codes in IL

Find all the active codes below of Illinois area codes organized by coverage area:

• 217 – Covers Springfield, Champaign, and surrounding areas
• 309 – Western central Illinois
• 312 – Downtown Chicago only
• 773 – Northwest and South Side of Chicago
• 872 – Overlay for 312 and 773
• 847 – North Chicago suburbs
• 224 – Also covers northern suburbs
• 630 – Covers DuPage County, Naperville, Wheaton
• 331 – Used in the same region
• 708 – Southwest Chicago suburbs
• 815 – Spans northern rural regions
• 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.

Illinois Area Code Search Tools

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

Illinois Virtual Numbers for Businesses

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

Using VoIP and virtual phone systems, getting a number with an Illinois area code is now easy and affordable.

If you're setting up a professional phone system with a local presence, explore Illinois-based VoIP services from Bling.

New and Duplicate Area Codes in IL

To prevent exhaustion of available numbers, Illinois has implemented overlays in many regions.

These are the current overlays used in Illinois:

• 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

Illinois is divided into three primary telephone Illinois area code changes 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.

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

Get a Business Number with an Illinois Area Code

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

For example, Illinois business line instantly connects you with your target region.

Explore get a virtual Illinois number today.

Illinois Area Code: Common Questions Answered