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How to find the number behind “no caller ID”

An incoming call labeled “no caller ID” on your phone means that the person trying to reach you is deliberately concealing their identity from you. Because the call is purposely anonymous, it’s hard to find out the number behind it.

Let’s face it: discovering the person behind a “no caller ID” is a challenge and may not always be possible. Depending on whether you received the call on your cell phone or on a landline phone, these are the options available to you:

• On a landline phone: call trace (*57), or call return (*69) if the number wasn’t hidden on purpose.
• On a cell phone: your only option is a third-party app.

Let’s look at each of these solutions in detail.

Dorota Martin

Updated on: 30 September, 2026

How to find no caller ID on a landline phone

There are essentially two things you can do if a “no caller ID” displays on your handset. 

1) Dial *69 or equivalent for call return

If you’re in the US, the *69 feature lets you call back the last person who called you; in the UK, it’s 1471.

Once dialed, a voice recording will give you the number and exact time of the last received call. You can jot the number down in order to report it, or call them back.

There’s a limit to this, though. Carriers won’t announce or dial back a number that the caller marked as private, so *69 only helps when the number went missing for some other reason, such as a network fault. The UK’s 1471 behaves the same way: if the caller withheld their number, the recording tells you that, and nothing more. For a call that was hidden on purpose, the second option is the one that applies.

2) Malicious call identification or *57

Call tracing services can notify your service provider of an unknown caller’s identity if the caller is threatening or harassing you. Dial *57 to trigger a caller ID trace request. Your phone service provider will trace the call and log the number internally, even though the caller’s number is hidden from you directly.

There are three important things to be aware of here:

• If your service provider can trace the call, you will most likely be charged for it.
• The phone number you asked to identify will be known to the provider but not disclosed to you.
• Lastly, the number will not be automatically reported to the government agency responsible for managing these calls. You will need to report the incident to the police first, and your phone service provider will release the traced number to law enforcement upon formal request.

Both the *69 and the *57 features are built into landline phones only.

How to find “no caller ID” on iPhone & Android

There’s essentially one way to find out what the “no caller ID” number is on a mobile line, and that’s with the help of a third-party app, if you’re lucky. However, like with most apps, your data becomes the currency.

It’s worth separating two kinds of app here, because they don’t do the same job. A caller ID app gathers information from databases, online platforms, social media, and other sources, and matches an incoming number to a name—which means it needs a number to work with in the first place. An unmasking service works differently: it reroutes the call so that the number is handed over to it. Only the second kind can do anything with a “no caller ID” call.

Like with all apps, you have to be very careful about the permissions you grant. Apps usually collect many data points, so it’s best to use these services as sparingly as possible.

TrueCaller

TrueCaller claims to identify “each incoming call anywhere in the world.” It’s probably the most popular call identification app, and you can download it from the Apple store for free.

It won’t unmask a “no caller ID” call, though. TrueCaller matches visible numbers against its own database, so a call that arrives without a number gives it nothing to look up.

It’s also owned by a company that profits from aggregating and reselling caller data, which runs counter to the privacy goal you’re trying to achieve.

The app will require access to your contacts. You will also need to select it as your call identification service in your iPhone settings. Once you confirm your phone number, other TrueCaller users will be able to identify you by name when you call them, too.

The privacy policy clearly states that others will be allowed to see your personal information when looking up your number. This is followed by a request for you to consent to cookies. The list of vendors that can potentially access your data is extensive.

So it isn’t the tool for this particular job, and it carries a privacy cost of its own. We’d leave it alone.

TrapCall

TrapCall doesn’t look numbers up. It uses a carrier feature called conditional call forwarding, which passes calls you decline or ignore on to a second number of your choosing. TrapCall sets its own toll-free number as that destination.

That’s what makes it work: caller ID blocking doesn’t apply to toll-free numbers, because the toll-free line is the one being billed for the call and has to be told where it came from. So when a declined “no caller ID” call reaches TrapCall’s toll-free line, the number arrives with it. TrapCall then rings you back, this time with the caller’s real number showing.

TrapCall helps you discover the person hiding behind “no caller ID” if the incoming call is from the US (the service isn’t available outside it). TrapCall will send you details about the caller after unmasking the number.

It doesn’t work in every case, though. Your carrier has to offer conditional call forwarding in the first place, and callers using internet calling services with their number blocked can’t always be unmasked—TrapCall shows a placeholder number instead.

In its privacy policy, TrapCall assures its users that it doesn’t sell personal information. However, quite a lot is shared. Your data will be shared with “professional advisors providing advice or otherwise protecting” the company’s interests, among other categories.

How to report or reduce “no call ID” incoming calls

You won’t always be able to find the number behind a “no caller ID” call. Fortunately, there are ways to manage these calls without identifying the caller.

Report unwanted calls to the Federal Trade Commission (FTC)

Don’t let fraudsters get away with scam calls, even if they are “just” a nuisance. You can report unwanted calls to the Federal Trade Commission’s registry. Go to https://www.donotcall.gov/ and select “report unwanted calls.”

Register with the National Do Not Call Registry 

It won’t work for scam calls, but you can reduce spam calls, robocalls, and unwanted calls by registering your number with the National Do Not Call Registry.

Why blocking “no caller ID” calls on a cell phone doesn’t work

Unfortunately, there is no dedicated setting to block a specific “no caller ID” caller on a cell phone. That’s because only callers with visible numbers can be blocked.

What you can do is turn away everyone who’s hiding: Android phones have a setting for blocking unknown or hidden numbers, and iPhones can silence or screen unknown callers instead. Both are all-or-nothing, though—they’ll catch a doctor’s office or a delivery driver along with the caller you’re trying to avoid. For the steps, see our guides to blocking spam calls on iPhone and Android.

Check out our other article to find out how to block private numbers.

What does “no caller ID” mean and how is it different from “unknown caller”?

“No caller ID” means the caller has purposely disabled their caller ID so it doesn’t display on your phone. It also means that you won’t be able to call them back.

“No caller ID” is used by some professions and organizations for privacy reasons. However, many “no caller ID” calls are scams where callers hide their numbers to avoid detection. It’s best not to pick up unless you were expecting the call.

On the other hand, “unknown caller” displays when the phone carrier cannot identify the number due to technical limitations. Essentially, the caller’s number hasn’t intentionally been blocked.

Check our article about the difference between “unknown caller” and “no caller ID” to learn more.

Get to the root of the problem

Unmasking one caller won’t stop the next one. Anonymous callers usually aren’t dialing at random: your number, and often your address and the names of your relatives, sit in files that data brokers sell on to anyone willing to pay for them.

Removing your details from those files won’t unmask anyone either, but it does deal with the part you can actually control—how easily a stranger gets hold of your number in the first place. Incogni sends removal requests to 420+ data brokers on your behalf, then keeps checking that your records stay off their lists.

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• What is Dynata? Why are they calling?
• How to block a number on a landline
• Why are you getting so many spam calls all of a sudden?
• What are potential spam calls & how to block them

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