Area code 331 — Aurora, Illinois

Where is area code 331?

Area code 331 is in Aurora, Illinois, covering Aurora and surrounding communities in Illinois. All 331 numbers are on Central Time.

Is area code 331 a scam?

No. Area code 331 is a legitimate area code serving Aurora since 2007. Scammers spoof caller ID to display 331 numbers, which is why complaints exist against a code that is itself genuine.

Neighbour spoofing is the reason a local-looking number is not a guarantee. A caller anywhere in the world can display a 331 number, and the number they display may belong to a real business in Aurora that has nothing to do with the call.

• ·Area code 331 had 164 different numbers reported for spam calls in the 30 days to 28 July 2026.
• ·Area code 331 ranks 277th of 331 US geographic area codes by spam complaint volume.
• ·Of the 686 complaints about area code 331 in the 30 days to 28 July 2026, 83% were reported as a recorded message or robocall.
• ·The most reported subject on area code 331 is reducing your debt (credit cards, mortgage, student loans), appearing in 55% of its complaints in the 30 days to 28 July 2026.

What these calls were about

Each figure is that subject’s share of every 331 complaint in the 30 days to 28 July 2026, as categorised by the consumer who reported it.

Businesses can prevent their own numbers from being mistaken for calls like these.

Why am I getting text messages from area code 331?

Texts from 331 numbers follow the same pattern as calls — mostly local businesses and services. Treat any text asking for payment or credentials as suspect regardless of the code.

The common patterns are a wrong-number opener that turns into conversation, an unsolicited job offer, and a crypto or investment tip. Do not reply, do not follow the link, and forward the message to 7726 (SPAM) to report it to your carrier.

Area codes that overlay 331

Area code 331 shares its geographic footprint with one other code: 630. Overlays are laid over an existing area rather than splitting it, so all local calls require the full ten-digit number.

Who works in the Aurora area?

Aurora is the second-largest city in Illinois and the western anchor of Chicago's suburban economy. Its industrial base runs to manufacturing, logistics, and healthcare, with the Hollywood Casino and the restored Paramount Theatre pulling entertainment spending into a downtown that has been rebuilding itself along the Fox River. The corridor gained area code 331 in 2007 as an overlay on 630, covering Aurora, Naperville, and the DuPage County corridor, one of the most commercially dense suburban stretches in the Midwest. A 331 number is simply the newer issue in the same territory.

Who lives in the 331 region

The area's households are notably well off for a manufacturing city. DataUSA recorded 179,898 residents in Aurora in 2024, with a median household income of $93,633 and a poverty rate of 9.52 percent. Employment stood at 95,533. The city is one of the most diverse in Illinois, with a large Spanish-speaking population, and businesses in Aurora, Illinois routinely serve customers in both English and Spanish. Corporate offices and distribution centers along the Interstate 88 corridor add a white-collar and logistics layer to the older industrial base.

What a 331 number signals to a caller

Callers familiar with the region describe suburban Chicago phone behavior as brisk. People answer for numbers they recognize, and the 630 and 331 codes are treated as one and the same by locals, who have dialed ten digits since the overlay took effect. Business calls placed during the workday to this corridor reach office workers and shop floors on Central Time schedules, and callers who state their business quickly are generally received better than those who open with pleasantries.

Questions