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 covers all major and minor Illinois area codes

Whether you're a resident, traveler, or business owner, knowing the dialing system across IL is central Illinois area codes essential for seamless contact and verification.

Understanding Illinois Area Codes

Area codes in Illinois are three-digit numbers assigned to different regions, supporting phone number management for personal and business use.

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

Below is a current list of Illinois area codes organized by coverage area:

• 217 – Central Illinois including Springfield
• 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 – North Chicago suburbs
• 224 – Also covers northern suburbs
• 630 – Covers DuPage County, Naperville, Wheaton
• 331 – Used in the same region
• 708 – Oak Lawn, Cicero
• 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

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

Why Businesses Choose Local Illinois Numbers

Entrepreneurs and service providers rely on local numbers to appear local and trustworthy in customers’ eyes.

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 number options today.

New and Duplicate Area Codes in IL

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)

Users must now dial 10 digits, even for local calls, due to overlays.

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

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

This flexibility helps businesses scale, reach target markets, and streamline support.

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.

Explore VoIP number options for Illinois today.

Illinois Area Code: Common Questions Answered