How to Block a Phone Number and Hide Your Own Caller ID

Step by step

1. 1

   Android: block a number from the call list

   Open the Phone app and go to Recents. Long-press the number or tap the info icon, then choose Block or Block/report spam. You can also block a number by opening the contact and choosing Block from its menu.

2. 2

   iPhone: block a caller

   In the Phone app, go to Recents, tap the info icon next to the number, and scroll to the Block this Caller option. You can do the same from Contacts or from a conversation in Messages. Once confirmed, the number can neither call you nor send you a text.

3. 3

   Hide your number for a single call

   To call with your number hidden just once, dial #31# right before the number, for example #31#600100200, and place the call. The recipient sees No Caller ID instead of your actual digits. On the next call, your number is visible again, unless you hide it permanently.

4. 4

   Hide your number permanently

   On an iPhone, go to Settings, Phone, and turn off the Show My Caller ID option. On Android, look in the Phone app settings for the caller ID section and choose Hide number - the path depends on the model. If the option isn't there, ask your carrier for a permanent caller ID block.

5. 5

   Undo the block or show your number

   You unblock numbers on the blocked list: on iPhone in Settings under the Phone section, on Android in the Phone app settings. To show your hidden number for a single call, dial *31# before the number. To remove permanent hiding, switch Show My Caller ID back on or ask your carrier to do it.

6. 6

   Check that the hidden caller ID actually works

   After setting up permanent hiding, call someone you know and ask what they see on screen. They should see No Caller ID instead of your actual digits. If your number still shows up, enable the caller ID block on the carrier's side, because some networks override the phone setting.

Blocking someone's number vs hiding your own - two different things

Blocking a number applies to someone else: you make sure a given number can't call or text you. Hiding your caller ID applies to your own number - you conceal your digits when calling other people. They're two separate features that are easy to mix up, because both revolve around number visibility.

After you block someone, their calls usually don't ring and land in voicemail, and their texts never reach your inbox. The caller usually gets no clear message that they've been blocked - they hear normal ringing tones or go straight to voicemail. The block works only on your phone, so it doesn't change how others see that number.

The #31# and *31# codes and carrier-side caller ID blocking

Dialing #31# before a number hides your caller ID for that one call, while *31# does the opposite: it shows your number even when permanent hiding is switched on. That's handy when you normally call with a hidden number but want your bank or a government office to see who's calling. Enter the codes directly before the digits, with no spaces.

You can set permanent hiding on the phone, but the most reliable option is enabling it on the carrier's side as a caller ID block. It then works regardless of the phone, including after you switch devices. Emergency numbers and some hotlines will see your number anyway, because safety rules require it.

Carrier-level blocking and messaging apps

A block set on your phone works only on that device, so after switching phones you have to set it up again. If you want a harder barrier, some carriers let you filter spam or block calls at the network level - ask their hotline or check the carrier's app. A block like that works regardless of your phone model.

Messaging apps are a separate matter. Blocking someone on your phone won't block them on WhatsApp, Messenger, or Signal - there you switch the block on separately, in the settings of the given conversation or profile. If you want to cut off contact completely, go through every app where that person can reach you.

Frequently asked questions