Complete Guide to Illinois Phone Area Codes

Are you wondering what area code corresponds to your Illinois city? You’ve come to the right place—this blog includes everything from historical area code changes to VoIP business solutions

From local users to virtual phone system seekers, knowing the dialing system across IL helps with routing calls, marketing, and compliance.

How Illinois Phone Codes Work

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

Illinois Area Code List

Here is a breakdown of the current area codes used across Illinois:

• 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 – 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.

How to Lookup Illinois Area Codes

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

Entrepreneurs and service providers rely on local numbers 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.

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

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)

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

How VoIP Is Changing Illinois Phone Systems

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

Whether you're in downtown Chicago or remote southern Illinois, you can now get a local area code with VoIP solutions.

Get a Business Number with an Illinois Area Code

Local numbers are critical for customer trust.

You can register a business phone number with any Illinois code through platforms like Bling.

You don’t need to be in Illinois physically—virtual systems handle routing through VoIP or read more PBX networks.

Illinois Area Code: Common Questions Answered