Unknown caller: what it means and what to do about it

When your phone shows "Unknown", "No Caller ID" or "Private number", it has no number or name to display. Sometimes that's harmless. A doctor's office, a hospital or a company switchboard may hide its number on purpose. The FCC points out that callers are legally allowed to hide their number, and that hiding it is not the same as spoofing.

Unknown caller vs. spoofed caller

With an unknown caller, there's nothing on the screen. With spoofing, the screen shows a number, but it's a fake one chosen to make you pick up, often a local number or a name you trust. The FCC defines spoofing as deliberately falsifying the information sent to your caller ID display to disguise the caller's identity. So a number on your screen doesn't prove who is calling either. The FTC warns that even a local-looking number can be a scammer calling from anywhere in the world.

Why scammers and marketers use hidden numbers

A hidden number makes a call harder to report and block. Robocallers and scammers use it, along with spoofing, to get you to answer. Once you do, the call may be a recorded pitch, or a person posing as your bank, a government agency or tech support and asking for personal or financial details.

A typical case: your phone rings with no caller ID, a voice says your account is locked and asks you to confirm your date of birth. Any real bank will let you hang up and call back on the number printed on your card.

What the call can lead to

An answered call can tell a robocaller your number is live, which tends to bring more calls. A scam call can lead to money lost or personal details handed over, which feed identity theft.

Not every unknown call is bad, and blocking all of them has a cost. The FCC notes that a blanket block can also stop calls you want, such as from a clinic or a delivery driver.

How to protect yourself

Don't engage, and don't press buttons

The FTC says to hang up on an illegal robocall and not press any key, including the one that promises to remove you from the list. Responding tends to bring more calls.

Use your phone's built-in screening

iPhones have an opt-in Silence Unknown Callers feature and Google Pixel phones have Call Screen, per the FCC. Calls from unknown numbers go to voicemail, so you can listen first. Check voicemail now and then if you're expecting a call from a clinic or an employer.

Verify by calling back on a number you trust

If someone claims to be from your bank or a government agency, hang up and call the number on your statement, your card or the organization's official website. Never share personal or financial details on a call you didn't start.

Register and report

Add your numbers to the free National Do Not Call Registry at donotcall.gov and report unwanted calls at ReportFraud.ftc.gov. Do Not Call stops honest telemarketers; scammers ignore it, so don't count on it alone.

Make your number harder to find

Your phone number sits on many people-search sites, which marketers and scammers use as call lists. Serus finds where your phone number is listed and removes it. Fewer listings can mean fewer calls over time.

Frequently asked

Is a call from "no caller ID" always a scam?

No. Some businesses and medical offices hide their numbers. But a scammer can hide theirs too, so judge the call by what it asks for, not by the display. Anything that asks for money, passwords or codes is a red flag.

Can I find out who an unknown caller is?

If the number is hidden, usually not. If a number is shown, it may be spoofed. The safer move is not to answer, and let a real caller leave a voicemail.

Should I block all unknown callers?

You can, and it will cut a lot of junk. The catch, as the FCC notes, is that legitimate callers who hide their number get blocked too.

Does answering an unknown call put me at risk?

Answering alone rarely does harm, but it can show a robocaller that your number is active. The bigger risk is what you say or press during the call. Hang up on anything suspicious.

What is an unknown caller?