Everything You Should Know About Illinois Area Codes

Need to identify or obtain an Illinois-based phone number? You’ve come to the right place—this blog dives into lookup tools, city-based breakdowns, and more.

From local users to virtual phone system seekers, grasping the phone number structure in Illinois is essential for seamless contact and verification.

Understanding Illinois Area Codes

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

Administered by the North American Numbering Plan Administration (NANPA),, Illinois codes align with the NANP guidelines used across North America. For official standards, visit NANPA’s website.

Illinois Area Code List

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

• 217 – Covers Springfield, Champaign, and surrounding areas
• 309 – Western central Illinois
• 312 – Central Chicago zone
• 773 – Northwest and South Side of Chicago
• 872 – Covers greater Chicago metro
• 847 – North Chicago suburbs
• 224 – Overlay for 847
• 630 – Western suburbs
• 331 – Overlay for 630
• 708 – Southwest Chicago suburbs
• 815 – Spans northern rural regions
• 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.

Illinois Area Code Search Tools

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

Using Illinois Phone Codes for Business Presence

Businesses operating in or targeting Illinois use local area codes to establish trust, improve response rates, and localize presence.

With services like Bling Cloud, businesses can instantly activate virtual numbers for any Illinois region.

If you're setting up a professional phone system with a local presence, explore business phone systems from Bling.

Overlay Area Codes in Illinois

To prevent exhaustion of available numbers, Illinois has implemented overlays in many regions.

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 Cook County area code overlays.

Regional Breakdown: Northern, Central, and Southern Illinois Area Codes

Here’s how the area codes are split by region in Illinois:

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.

Want to learn more? Visit Illinois VoIP phone solutions for powerful options.

Buying an Illinois Local Business Number

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

For example, Illinois business line instantly connects you with your target region.

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

FAQ – Illinois Phone Codes