Everything You Need to Know About Illinois Phone Area Codes

Illinois Area Codes Explained

Trying to understand which area code to use for your business in Illinois? You’ve come to the right place—this blog dives into lookup tools, city-based breakdowns, and more.

Whether you're a resident, traveler, or business owner, knowing the dialing system across IL helps with routing calls, marketing, and compliance.

What Are Area Codes in Illinois?

The area code system in Illinois segments regions for organized call routing, helping manage number allocation across cities.

Supervised by NANPA and Illinois telephone codes the FCC,, 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

Here is a breakdown showing city coverage and overlays:

• 217 – Central Illinois including Springfield
• 309 – Peoria, Bloomington, and western parts of IL
• 312 – Central Chicago zone
• 773 – Rest of Chicago outside downtown
• 872 – Overlay for 312 and 773
• 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 – Same coverage region
• 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

There are many reliable lookup tools 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

Companies looking to reach customers in Illinois often opt for 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

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

Illinois Area Codes & VoIP Technology

With the rise of cloud calling, VoIP is becoming the preferred method for phone communication in Illinois.

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

Getting a business phone number with an Illinois area code enhances regional credibility.

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

Explore get a virtual Illinois number today.

Frequently Asked Questions About Illinois Area Codes