Complete Guide to Illinois Phone Area Codes

Need to identify or obtain an Illinois-based phone number? This detailed guide covers all major and minor Illinois area codes

From local users to virtual phone system seekers, knowing the dialing system across IL helps with routing calls, marketing, and compliance.

Understanding Illinois Area Codes

Illinois telephone area codes identify specific geographic territories, helping manage number allocation across cities.

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

Illinois Area Code List

Find all the active codes below of the current area codes used across Illinois:

• 217 – Central Illinois including Springfield
• 309 – Western central Illinois
• 312 – Central Chicago zone
• 773 – Northwest and South Side of Chicago
• 872 – Overlay for 312 and 773
• 847 – North Chicago suburbs
• 224 – Overlay for 847
• 630 – Covers DuPage County, Naperville, Wheaton
• 331 – Overlay for 630
• 708 – Southwest Chicago suburbs
• 815 – Rockford and northern IL
• 779 – Same coverage region
• 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 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

Companies looking to reach customers in Illinois often opt for local numbers to appear local and trustworthy in customers’ eyes.

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 cloud phone platforms 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

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

Illinois Area Codes & VoIP Technology

VoIP lets you use any area code in Illinois without a physical presence.

Want to learn more? Visit VoIP-powered Illinois business calling for powerful options.

Get a Business Number with an Illinois Area Code

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.

Frequently Asked Questions About Illinois Area Codes