Complete Guide to Illinois Phone Area Codes

Trying to understand which area code to use for your business in Illinois? 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.

What Are Area Codes in Illinois?

Area codes in Illinois are three-digit numbers assigned to different regions, allowing calls to be directed accurately.

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

Active Area Codes in IL

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

• 217 – Central Illinois including Springfield
• 309 – Western central Illinois
• 312 – Central Chicago zone
• 773 – Rest of Chicago outside downtown
• 872 – Overlay for 312 and 773
• 847 – Northern suburbs including Evanston
• 224 – Also covers northern suburbs
• 630 – Western suburbs
• 331 – Overlay for 630
• 708 – Southwest Chicago suburbs
• 815 – Rockford and northern IL
• 779 – Overlay for 815
• 464 – Newest overlay for Chicago

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

Find Area Codes for Illinois Cities

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 establish trust, improve response rates, and localize presence.

Modern business platforms make it simple to buy or assign IL-based numbers.

Looking to get started? Check out Bling’s virtual phone numbers today.

Illinois Area Code Overlays

Many IL area codes now have overlays due to high population and business new Chicago area code 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)

Overlay codes don’t replace old ones but coexist in the same region.

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

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.

Buying an Illinois Local Business Number

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 PBX networks.

Illinois Area Code: Common Questions Answered