How to block text messages from unknown numbers

If your phone is overrun with spam text messages from random unknown senders, it’s understandable that you’re looking for solutions. Not only does it make finding messages you actually want to read difficult, but you also suffer constant disruptions throughout the day.

Stopping spam on your phone can be tricky. But we’ll help you block messages from unknown numbers—whether you have an iPhone or Android device, use only your default messaging app, or prefer other apps like Viber.

In this guide, we’ll focus on blocking messages from unknown numbers. For tips on stopping spam texts in general, click here.

Adam Cholinski

Filter unknown senders on Android

1. Open your phone app. 
2. Tap “more” and go to “settings.”
3. Tap “blocked numbers” and turn on “unknown.”

If you’re using the Messages by Google app, you can also filter out spam. This is the default messaging app on many Android phones but if you don’t have it, you can download it from the Google Play store. 

1. Open the Messages by Google app. 
2. Tap the three dots in the top-right corner.
3. Tap “settings.”
4. Tap “spam protection.”
5. Enable the spam protection feature under the “spam protection” settings.

Filter unknown senders on iPhone

1. Open your messages app.
2. Tap “filters” in the top-left corner.
3. Select “unknown senders.”

Turn off notifications on spam texts:

1. Open settings.
2. Tap “notifications.”
3. Tap “messages.”
4. Go to customize notifications and disable notifications for unknown senders.

Related: How to block calls from private numbers

Block spam from unknown senders through your messaging apps

Once you’ve effectively blocked unknown numbers on your device and default messaging app, you should do the same with whatever other messaging apps you use. We’ve covered the most popular ones below. However, if you use an app we haven’t covered, we recommend checking the settings for similar options. 

WhatsApp

Unfortunately, WhatsApp doesn’t provide any options to filter out messages from unknown senders. What you can do instead is silence unknown callers and block specific numbers that send you unwanted messages. 

To silence unknown callers:

1. Open WhatsApp. 
2. Tap the three dots in the top-right corner. 
3. Select “settings.”
4. Tap “privacy.” 
5. Scroll down and tap “calls.”
6. Enable the silence unknown callers feature. 

To block specific senders:

1. Open WhatsApp. 
2. Long press on the conversation from the sender you want to block to select it.
3. Tap the three dots in the top-right corner. 
4. Select “block.”

Telegram

Telegram offers two options that can help you limit the number of messages you receive from unknown numbers. You can hide your phone number and restrict who can add you to groups (therefore limiting spammers who send out mass messages). 

To hide your number: 

1. Open Telegram. 
2. Tap the hamburger menu icon in the top-left corner (in the bottom-right corner on iPhone).
3. Go to “settings.”
4. Scroll down and tap on “privacy and security.” 
5. Under privacy, tap “phone number.”
6. Select “my contacts” or “nobody.”
7. Tick the checkmark to confirm your choice (tap the back button on iPhone).

To restrict who can add you to groups:

1. Open Telegram. 
2. Tap the hamburger menu icon in the top-left corner (in the bottom-right corner on iPhone). 
3. Go to “settings.”
4. Scroll down and tap on “privacy and security.” 
5. Under privacy, tap “Groups & Channels.”
6. Select “my contacts” under “who can add me to group chats.”
7. Tick the checkmark to confirm your choice (tap the back button on iPhone).

Viber

1. Open Viber. 
2. Tap “more” in the bottom-right corner. 
3. Tap “settings.”
4. Tap “calls and messages.”
5. Scroll down and untick “receive business messages.”
6. Go back to the previous screen and tap “privacy.”
7. Scroll down and tap “control who can add you to groups.”
8. Select “my contacts.”

Related content

• How to stop spam texts
• How to block texts from emails addresses
• How to report spam text
• How to identify a fake text message

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