Everything You Should Know About Illinois Area Codes

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.

No matter if you’re launching a business or tracing a call, understanding Illinois’ telephone code system is essential for seamless contact and verification.

What Are Area Codes in Illinois?

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

Supervised by NANPA and the FCC,, Illinois codes align with the NANP guidelines used across North America. For official standards, visit NANPA’s website.

Current List of Illinois Area Codes

Below is a current list showing city coverage and overlays:

• 217 – Central Illinois including Springfield
• 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 – Overlay for 847
• 630 – Western suburbs
• 331 – Used in the same region
• 708 – Oak Lawn, Cicero
• 815 – Spans northern rural regions
• 779 – Same coverage region
• 464 – Newest overlay for Chicago

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

How to Lookup Illinois Area Codes

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

Using Illinois Phone Codes for Business Presence

Businesses operating in or targeting Illinois use local area codes to appear local and trustworthy in customers’ eyes.

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 Illinois-based VoIP services from Bling.

Illinois Area Code Overlays

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

Illinois is divided into three primary telephone 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.

How to Get a Local Number in Illinois

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

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

Explore VoIP number options for Illinois today.

Illinois Area Code: Common Questions Answered