Seeing calls from 331 and asking whether area code 331 is a scam? Area code 331 is a genuine U.S. area code serving the western suburbs of Chicago, Illinois (overlay of 630). The code itself is safe, but scammers routinely spoof 331 numbers so their calls appear local and trustworthy. This guide covers the spam and text risks reported for 331, how to verify unknown callers, and how to block and report them.
✅ Quick Safety Verdict
Is 331 an official US area code? Yes—331 is a valid NANP area code serving Chicago’s western suburbs. Is it safe to answer? Yes if you recognize the number. Because scammers spoof local 331 numbers, treat unexpected calls from unknown 331 numbers with caution and never share personal or financial details with an unverified caller.
Area Code 331 Fast Facts
| Detail | Information |
|---|---|
| Location Covered | the western suburbs of Chicago, Illinois (overlay of 630) |
| Time Zone | Central Time (CT, UTC-6 / UTC-5) |
| Spoofing Risk Level | High |
| Official Carrier Info | Assigned under the NANP; overlays the 630 western-suburban Chicago code. |
| Related Area Codes | 630 |
Common Scams Reported From Area Code 331
Neighborhood Spoofing
Scammers forge caller ID so a robocall appears to come from a local 331 number—sometimes matching your own first six digits—to boost the odds you answer. The real caller is often overseas or using an auto-dialer. If a “local” 331 call opens with a recording or a stranger asking for payment or personal data, hang up.
Phishing, Bank Impersonation & Impostor Scams
Fraudsters posing as your bank’s fraud department, the IRS, Social Security, or a utility company call from a 331 number claiming urgent action is required. They pressure you to “verify” account numbers, passwords, or one-time codes, or to pay with gift cards or wire transfer. Real institutions never demand those.
Text Message (SMS) / Smishing Alerts
Smishing texts from 331 numbers pose as package couriers, banks, or toll agencies with a link to “resolve” an issue. The links lead to fake login pages that harvest credentials. Do not tap links in unexpected texts; open the company’s app or type its website manually instead.
How to Identify & Verify Unknown Callers From 331
- Let it ring. Legitimate callers leave a voicemail; most scam auto-dialers do not.
- Search the number. Paste the full 10-digit number into a search engine or a reverse-lookup site to see if others reported it as spam.
- Check the location. A real 331 call should relate to Chicago’s western suburbs. Compare it with our area code 331 reference and the Aurora area code guide.
- Call back on an official number. If a caller claims to be your bank or a government agency, hang up and dial the number printed on your card or the agency’s official website—never the number that called you.
- Never share codes. No legitimate caller needs a one-time passcode, PIN, or password read aloud.
How to Block Calls & Report Scams
Block on iPhone (iOS)
Open the Phone app → Recents → tap the ⓘ next to the 331 number → scroll down and tap Block this Caller. To silence all unknown numbers, go to Settings → Apps → Phone → Silence Unknown Callers.
Block on Android
Open the Phone app → Recents → press and hold the 331 number → tap Block / report spam. In Settings → Spam and Call Screen, enable See caller & spam ID to filter suspected scams automatically.
Report to the FTC & DoNotCall.gov
Register your number free at DoNotCall.gov (or call 1-888-382-1222), then report unwanted or scam calls at ReportFraud.ftc.gov. Reporting the offending 331 number helps regulators trace robocall campaigns. You can also forward scam texts to 7726 (SPAM) to alert your carrier.
Frequently Asked Questions
Is area code 331 a scam?
No. 331 is a real U.S. area code serving Chicago’s western suburbs. Scammers do spoof 331 numbers, so judge each call on its content—not just the area code.
Why am I getting spam calls from 331?
Robocallers use neighbor spoofing to display a local 331 number so you are more likely to answer. The calls often originate elsewhere through auto-dialers.
Is it safe to answer calls from 331?
It is safe to answer numbers you recognize. For unknown 331 numbers, let them go to voicemail and never share personal or financial details with an unverified caller.
How do I stop 331 spam calls?
Block the number on your phone, enable your carrier’s spam filter, register at DoNotCall.gov, and report scam calls at ReportFraud.ftc.gov.
Related Guides
- Full number reference: area code 331
- Local area codes: Aurora area code guide
- Learn how caller-ID spoofing works and how to shut it down using the steps above.
More 331 & Related Resources
- Full number reference: 331 area code details.
- Local area codes: Aurora area code guide.
- Getting toll-free calls too? Compare our Toll-Free Numbers guides such as 800 and 888.
- More warnings in the Scam Alerts directory.