How do you call with hidden number /private? – Complete user guide

Whether you want to protect your privacy or simply want to joke with a friend, a hidden number call is an effective method. We show you how you can do this quickly and without complications.

What is a hidden number?

In the context of telecommunications, a hidden number is a phone call made from a number that is not displayed on the recipient’s screen. Instead of the phone number, the called user sees messages such as „Number unknown”, „Private number” or „Hidden number”.

This option is often used to protect the identity of the caller, either for privacy reasons or for professional reasons, such as in the case of calls made by institutions or firms that do not want to reveal their direct line.

What keys do I use for call with a hidden number?

The quickest way is to enter the code #31# before the phone number you want to call.
Example:
#31#074xxxxxxx

This method hides your phone number only for that call. The code works regardless of the mobile network used and cannot be „bypassed” of apps that claim to be able to display hidden numbers.

Set a permanent call with a hidden number on Android

If you want your number to be permanently hidden on calls made, follow the steps:

Go to Settings from the phone menu.

Select Apps → Settings apps system.

Choose Call Settings → Caller ID.

Select the option Hide number (Hide number).

To return to the normal number display, follow the same steps and select the Default network (Network default) option.

Quick codes for Android:

There are quick codes (USSD) for Android phones that allow you to control the phone number display feature when making calls.

Check the status of the hidden number: *#31#

→ This code shows you whether the number hide function is enabled or not. After you type it and press the call, you will receive a message on the screen with the status: enabled or disabled.

Permanently enable hidden number: *31#

→ This code activates the call function with hidden number for all the calls you will make on that phone. The people you call will not see your number.

Turn off the hidden number: #31#

→ This code disables the number hide function. After typing, your number will be visible again when you make calls.

Set a permanent call with a hidden number on iPhone (iOS)

For iOS users, follow these steps:

Go to Settings.

Select Phone → Show caller ID (Show my caller ID).

Turn off the option so that the cursor turns white.

To display the number again, turn on the option, and the cursor will turn green.

How do I block hidden number calls?

If you are bothered by calls from hidden numbers, here’s how to block them:

Android: Go to the Phone app, go to Settings, then Blocked Numbers, and turn on the lock option for hidden numbers.

iOS: Go to Settings → Phone and turn on Unknown silent callers (Silence unknown callers). Unknown calls will be forwarded directly to voicemail.

Other questions about the hidden number:

Can I find out who called me with a hidden number?

Unfortunately, there is no safe or legal way to find out who called you with a hidden number. Avoid apps that promise this because most do not work and may compromise the security of your personal data.
Now you are ready to use the hidden number call and manage unwanted calls effectively!

Does the #31# code work on any mobile network?

Code #31# is a USSD standard code and works on most mobile networks, including those in Romania, such as Orange, Vodafone, Digi or Telekom.
However, in some cases, functionality may be limited by your phone model or network settings. If it does not work, it is recommended that you consult your operator’s customer service. And if you are looking for a better phone, Klap can help you!

Do apps that show who is calling you with a private number work?

Most apps that promise to reveal the identity of a caller with a private number are misleading or over promoted. Technically, if the number is blocked at the source (network), the app cannot disclose it. Pay attention to applications that require extended permissions – some may collect personal data.

What to do if you are threatened with a hidden number?

If you receive threatening or harassing calls from a hidden number, it is important to treat the situation seriously. Do not answer or continue the conversation. Write down the time and frequency of the calls and file a complaint with the Police.
Authorities may work with your carrier to identify the source of the call, even if the number is hidden. You can also turn on the call blocking feature from unknown numbers directly in your phone settings using the instructions above.

What are the most common reasons behind calling with a private number?

The most common reasons why someone calls with a hidden number are:

Identity protection – people or institutions that do not want to be called back.

Marketing campaigns or surveys – some firms use private calls to avoid blocking numbers.

Joke or harassment – some individuals use this method to bother without being identified.

Official calls – institutions (police, hospitals, banks) can use hidden number for privacy.

Although some situations are harmless or justified, others can become abusive, which is why it is good to treat calls from hidden numbers with caution.