The 331 area code
The 331 area code covers Aurora, Naperville and Elmhurst in Illinois, in the Central time zone. Here is which cities use it, the current local time, the codes it overlays, how 331 numbers are written, and how to get a local 331 number for your business.
331 covers Aurora, Naperville and Elmhurst in Illinois. It sits in the Central time zone, where it is currently 10:27 PM. It shares that ground with 630, so ten-digit dialling is required. Numbers are written as (331) XXX-XXXX.
Where is the 331 area code?
The 331 area code serves Aurora, Naperville and Elmhurst in Illinois. It is one of the active area codes in the North American Numbering Plan, the system that assigns phone numbers across the United States, Canada, and nearby regions. A caller seeing a 331 number knows, at a glance, that the line is tied to Illinois.
What cities use the 331 area code?
331 is an overlay on 630, which means it was added over the same ground rather than carved out of it. So 331 numbers are handed out across the same places:
Aurora accounts for the largest share of 331 prefixes, with Naperville and Elmhurst next. A local number in any of them reads as local to everyone else on the list, because they all dial on 331.
Which area codes overlay 331?
331 is part of an overlay complex with 630. An overlay puts more than one area code over the same geography instead of splitting the region in two, so existing numbers keep their code and new ones get the added code. Two neighbours on the same street can hold different area codes. That is why ten-digit dialling is required here: you cannot assume a local call shares your area code.
What time is it in the 331 area code?
The 331 area code is in the Central time zone. Right now it is about 10:27 PM there. If you are calling a 331 number, check the local time first so you reach someone during business hours. If you run a business on a 331 line, missing a call after hours means the caller moves on to the next name on their list.
How to write a 331 phone number
A full 331 number is ten digits: the three-digit area code, then a three-digit prefix, then a four-digit line number. It is usually written as (331) XXX-XXXX, or 331-XXX-XXXX. To dial it from outside the United States, add the country code: +1 331 XXX XXXX.
Area codes near 331
These area codes also serve Illinois:
Getting a local 331 number for your business
People are far more likely to answer a call from a local number. If you do business in Aurora, Naperville and Elmhurst, a 331 number tells customers you are one of them, not an out-of-town call center. A virtual phone service can assign you a 331 number in minutes, no new hardware required.
The catch is answering it. A local number only helps if someone picks up. HiThisIs gives you a local number and a front desk that answers every call on the first ring, day or night, has a real conversation, and texts you the lead in seconds. It is a fraction of the cost of a human answering service, from $99 a month. See plans and pricing, or hear it answer on your own phone.
Common questions about the 331 area code
Where is the 331 area code?
The 331 area code covers Aurora, Naperville and Elmhurst in Illinois, in the Central time zone.
What cities use the 331 area code?
Aurora, Naperville, Elmhurst, Bensenville, Oak Brook, Bolingbrook, Wheaton and St. Charles all have numbering prefixes in 331. 331 overlays 630, so the two share the same geography.
What time zone is the 331 area code in?
The 331 area code is in the Central time zone. The current local time there is 10:27 PM.
Does 331 overlay another area code?
Yes. 331 is part of an overlay complex with 630. An overlay puts more than one area code over the same geography, which is why ten-digit dialling is required there: two neighbours can hold different area codes on the same street.
Is 331 a real area code?
Yes. 331 is an active North American Numbering Plan area code serving Aurora, Naperville and Elmhurst in Illinois.
How do I get a 331 phone number for my business?
A virtual phone service can assign you a local 331 number so customers in Aurora, Naperville and Elmhurst see a familiar area code when you call, and so your business looks local. HiThisIs includes a local number with every plan and answers it around the clock.