(331) Area Code Business Phone Numbers
The 331 area code covers Naperville and the western Chicago suburbs, sharing the same footprint as 630 since it was added as an overlay in 2007. Getting a 331 number tells local customers you are part of the neighborhood, not calling from three states away.
Get a 331 NumberAbout the 331 Area Code
The 331 area code arrived in 2007 as an overlay to 630, which had been running out of numbers as DuPage and Kane counties kept growing. That is why you now see both codes mixed together across the same towns, and why every local call in the region is a ten-digit call.
Naperville is the anchor city, and it is now the third-largest city in Illinois with roughly 153,900 residents [1]. The local workforce is unusually educated, with more than 72.8% of adults holding a bachelor's degree or higher [2], which helps explain why healthcare systems like Edward Hospital and distributors like KeHE sit alongside a deep bench of tech and professional services firms [2].
A 331 number matters because customers in Naperville, Aurora, and Wheaton still recognize the area code as theirs. A local number gets picked up more often than an out-of-state one, and it signals that you are close enough to show up if something goes wrong. Tonet lets you grab a 331 line without moving offices or swapping carriers.
Cities Served by the 331 Area Code
The 331 area code covers 25 cities across DuPage and Kane counties in the western Chicago suburbs. If your customers live west of the city, this is the code they know.
Phone Features Built for Western Suburb Businesses
Whether you are running a clinic near Edward Hospital or a contractor's office out of Aurora, these are the features that actually get used day to day.
Auto Attendant
Route callers to the right person before they hang up. Set different menus for daytime, evening, and the weekends your Naperville storefront is closed.
Call Recording
Keep a record of quotes, service calls, and disputes. Useful when a customer swears you promised a different price two weeks ago.
AI Transcription
Voicemails land in your inbox as searchable text. Skim ten messages between meetings instead of playing them one by one.
Business SMS
Text appointment reminders and quotes from your 331 number. Most western suburb customers reply faster to a text than a call.
Mobile App
Take business calls from your cell without giving out your personal number. Handy when you are on a job site in Batavia and the office is closed.
Daily Billing
You are charged per day for what you actually use, so hiring seasonal help does not lock you into a full month of extra seats.
Frequently Asked Questions
Is 331 the same coverage area as 630?
Yes. 331 is an overlay on 630, so both codes serve the same DuPage and Kane county towns. That is why callers in the western suburbs have to dial ten digits for every local call.
Can I keep my existing 630 or 331 number if I switch?
You can port it over. There is no downtime if the switch is scheduled correctly, and your existing customers keep dialing the same number.
Do I need a Naperville office to get a 331 number?
No. If you serve western suburb customers from anywhere, you can still get a 331 line. The number is tied to a virtual footprint, not a physical address.
How much does a 331 business line cost?
Plans start at $10 per user per month billed daily. Additional phone numbers are $2.50 each per month, and there are no contracts.
Will a 331 number work on my cell phone?
Yes. The Tonet mobile app puts your 331 line on any smartphone, so business calls stay separate from your personal number.
Ready to sound local in Naperville?
Pick a 331 number, plug in your team, and start taking calls the same day.
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