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, grasping the phone number structure in Illinois helps with routing calls, marketing, and compliance.

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, the state of Illinois adheres to NANP’s numbering scheme. For official standards, visit NANPA’s website.

Current List of Illinois Area Codes

Find all the active codes below of Illinois area codes organized by coverage area:

• 217 – Covers Springfield, Champaign, and surrounding areas
• 309 – Peoria, Bloomington, and western parts of IL
• 312 – Downtown Chicago only
• 773 – Rest of Chicago outside downtown
• 872 – Overlay for 312 and 773
• 847 – North Chicago suburbs
• 224 – Also covers northern suburbs
• 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

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.

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 virtual phone numbers today.

Illinois Area Code Overlays

Illinois uses overlay area codes to handle the increasing demand for phone numbers.

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

How VoIP Is Changing Illinois Phone Systems

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.

How to Get a Local Number in Illinois

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.

It’s also scalable for multiple team members and departments.

Frequently Asked Questions About Illinois Area Codes