Complete Guide to Illinois Phone Area Codes

Are you wondering what area code corresponds to your Illinois city? We’ll break it all down for you in this comprehensive post covers all major and minor Illinois area codes

From local users to virtual phone system seekers, understanding Illinois’ telephone code system is essential for seamless contact and verification.

Understanding Illinois Area Codes

Area codes in Illinois are three-digit numbers assigned to different regions, helping manage number allocation across cities.

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

Current List of Illinois Area Codes

Below is a current list of the current area codes used across Illinois:

• 217 – Central Illinois including Springfield
• 309 – Western central Illinois
• 312 – Central Chicago zone
• 773 – Northwest and South Side of Chicago
• 872 – Covers greater Chicago metro
• 847 – North Chicago suburbs
• 224 – Overlay for 847
• 630 – Western suburbs
• 331 – Used in the same region
• 708 – Southwest Chicago suburbs
• 815 – Rockford and northern IL
• 779 – Overlay for 815
• 464 – Launched to support number exhaustion

To learn more about official overlays and numbering plans, visit the FCC Area Code Resources.

How to Lookup Illinois Area Codes

You can use online tools that help you identify the area code for a city or trace a phone call.

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

Businesses operating in or targeting Illinois use local area codes to boost call pick-up rates and brand visibility.

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 business phone systems from Bling.

New and Duplicate Area Codes in IL

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

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 DuPage County area code 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

Illinois Area Codes & VoIP Technology

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

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

How to Get a Local Number in Illinois

Local numbers are critical for customer trust.

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.

Illinois Area Code: Common Questions Answered