How to Block Cell Phone Numbers

Maintain privacy and control over phone calls and messages

blocking caller ID
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Most smartphones offer the option to block a cell phone number in order to avoid receiving spam calls or other calls you don't want. Another option available is to block your own caller ID from displaying on the recipient's device.

Sometimes the operating systems hide these features deep in the settings. Further, different carriers offer various options for blocking numbers, so this feature is not always dependent entirely on the OS.

Blocking Incoming Phone Numbers

All major mobile phone operating systems offer a way to block a cell phone number.

iOS Phones

You can block numbers from within the phone's Recents section, within FaceTime or inside Messages. Blocking a number from one area blocks all three. From each area:

  1. Tap the "i" icon next to the phone number (or conversation).
  2. Select Block this Caller at the bottom of the Info screen.

    Warning: The Apple iOS only recently supported blocking incoming calls with 7.0 release, so any iOS users on an earlier version can block calls only by jailbreaking their phone.This requires using the alternative Cydia app repository to download and install an app that blocks numbers. Jailbreaking is not recommended, as it will void your warranty. Instead, try to upgrade to a newer OS version.

To view and manage blocked numbers:

  1. Navigate to Settings. 
  2. Tap Phone. 
  3. Tap Call Blocking & Identification.
  1. Then, either:
  • Select a phone number to view its details and select to either add or unblock the number or contact.
  • Add a contact to block by scrolling to the bottom of all blocked numbers and choosing Block Contact. This launches your contacts so you can select whom to block.

Filter iMessages: You can also filter your iMessages from people who are not in your contacts list.

Once you have filtered at least one message, a new tab displays for Unknown Senders. You still get the messages, but they won't be automatically displayed and you won't receive any notifications.

To filter iMessages:

  1. Navigate to Settings.
  2. Tap Messages.
  3. Turn on Filter Unknown Senders.

Android Phones

Because so many manufacturers produce phones that run the Android operating system, the procedure for blocking a number can vary widely. Further, versions of Android Marshmallow and older do not natively offer this feature. If you are running an older version like this, your carrier may support it, or you may be able to block a number using an app.

To see whether or not your carrier supports phone blocking:

  1. Open your Phone app.
  2. Select the number you want to block.
  3. Tap Call Details
  4. Tap Menu on the top right. If your carrier supports blocking, you'll have a menu item called something like "Block number" or "Reject call" or perhaps "Add to blacklist."

If you don't have an option to block a call, you might be able to at least send a call to voicemail:

  1. Open your Phone app
  2. Tap Contacts
  3. Tap a name.
  4. Tap the pencil icon to edit the contact.
  5. Select menu.
  6. Select All calls to voicemail.

To use a call blocking app:

Open the Google Play Store and search for "call blocker." Some well-regarded apps are Call Blocker Free, Mr. Number, and Safest Call Blocker.

Some are free and display ads, while some offer a premium version without ads.

Here are some tips for customizing Android in other ways. 

Windows Phones

Blocking calls on Windows phones varies.

For Windows 8:

Windows 8 uses the call+SMS filter app to block calls.

  • To activate the feature, first navigate to Settings and then call+SMS filter. Accept the terms and then click the Block calls+SMS toggle to turn it on.
  • To block a number, open the Phone app to see your call history. Long tap the number you want to block to view a context menu, and select block number.

For Windows 10:

Windows 10 uses the app Block and Filter, which allows you to manage blocked calls and messages.

  • To block a call or message, open the Phone or Messaging app, long-tap on the number you want to block, and select Block from the context menu. 
  • To manage how call blocking works, navigate to Settings | Extras | Block and Filter. Here, you can block calls that have no caller ID, and view your blocked calls and messages.

Blocking Your Own Number's Caller ID

In addition to controlling incoming calls via call blocking, you can also control whether an outgoing call will display your caller ID. This can be configured to operate as a permanent block or a temporary block on a call-by-call basis.

Warning: Your phone number can’t be blocked when calling toll-free (i.e. 1-800) and emergency services (i.e. 911), due to obvious security reasons.  

Call-by-Call Block From Caller ID

  1. Just dial *67 before the phone number on your cell phone. This code is the universal command to deactivate caller ID.

    For example, placing a blocked call would look like *67 555 555 5555 (without the spaces). On the receiving end, caller ID will usually display “private number” or "unknown." Though you won’t hear or see a confirmation of a successful caller ID block, it will work. 

Permanent Block From Caller ID

  1. Call your cell phone carrier and ask for a line block. This means your phone number won’t appear when you call any number. This is permanent and irreversible. While customer service may attempt to convince you to reconsider, the choice is yours. Various carriers support additional blocking features, such as blocking specific numbers or messages.

    Though the code to call your mobile carrier can vary, 611 typically works for cell phone customer service in the United States and Canada.
  2. If you temporarily want your number to appear when you have a permanent line block in place, dial *82 before the number. For example, allowing your number to appear in this case would look like *82 555 555 5555 (without the spaces).

    Do be aware, though, that some people automatically decline calls from phones that block caller ID. In that case, you’d have to allow caller ID in order to make the call.

Hide Your Number On An Android Device

Most Android phones provide a caller ID blocking feature in the Phone settings, available either through the Phone app or Settings | App Info | Phone. Some Android versions older than Marshmallow include this under an Additional Settings option within your Phone settings.

Hide Your Number On An iPhone

In iOS, the call blocking feature is under the Phone settings:

  1. Navigate to Settings | Phone
  2. Press Show My Caller ID.
  3. Use the toggle switch to show or hide your number.