WhatsApp is one of the most widely used messaging apps worldwide. While it’s a powerful tool for staying connected with friends, family, and colleagues, it can also become a channel for unwanted communication from unknown numbers. Fortunately, WhatsApp offers simple ways to block unknown contacts and enhance user privacy and security.
Blocking unknown numbers can help users avoid spam, scams, and unwanted conversations. Below is a guide on how to block unknown numbers on WhatsApp and keep your messaging experience clean and safe.
How to Block Unknown Numbers Manually
When a message arrives from an unknown number, WhatsApp immediately flags the sender as someone not in your contact list. Here’s how users can block such numbers manually:
- Open WhatsApp and tap on the chat from the unknown number.
- At the top, the app displays an alert message like “This number is not in your contacts.”
- Tap Block to prevent the sender from contacting you again.
- Optionally, you can tap Report and Block if you suspect spam or fraudulent activity.
This process applies to both Android and iOS devices. Once blocked, that number can no longer send messages or view your profile updates and last seen status.

How to Block Unknown Numbers After Receiving a Call or Message
If you’ve already received a call or message and failed to block the number initially, you can still take action:
- Go to the chats tab and open the conversation with the unknown number.
- Tap on the contact number at the top of the screen to open their profile.
- Scroll down and tap Block. Confirm the action when asked.
This will ensure that the blocked number cannot reach out again via chat or call on WhatsApp.
Auto-Blocking Unknown Numbers
WhatsApp currently does not offer a built-in feature that automatically blocks all unknown numbers. However, there are several privacy settings that can restrict interactions with people outside your contact list:
- Go to Settings > Privacy
- Choose from categories like Last Seen, Profile Photo, About, and Status
- Select My Contacts or My Contacts Except… to limit visibility
While this won’t block unknown numbers from messaging you, it minimizes their access to your personal information.

Using Third-Party Applications
Though not officially recommended, some users install third-party apps to manage unwanted calls and messages more effectively. These apps can offer features like call filters and auto-blocking of unfamiliar numbers. However, such apps must be used with caution due to privacy and security concerns.
Maintaining Privacy Settings
To further enhance protection from unknown contacts, users are advised to adjust their WhatsApp privacy settings:
- Disable Group Invites from Anyone: Go to Settings > Privacy > Groups and change the settings to My Contacts or My Contacts Except…
- Two-Step Verification: Enable this feature under Settings > Account > Two-step verification to add an extra layer of security
Regularly reviewing your privacy settings ensures that your WhatsApp experience remains safe from unfamiliar intrusions.
FAQ: Blocking Unknown Numbers on WhatsApp
- Can people tell if they’ve been blocked?
- No, WhatsApp does not notify users when they are blocked. However, blocked users may notice that messages are no longer delivered and profile information is no longer visible.
- What happens when I report and block a number?
- The number is blocked from contacting you again, and WhatsApp receives a report that may help in identifying and restricting spam or abusive behavior.
- Will blocking a number delete the chat?
- No, blocking a number does not delete the existing conversation. You will have to manually delete the chat if you wish to remove it from your chat list.
- Is there a way to block multiple unknown numbers at once?
- Currently, users have to block each number individually on WhatsApp. There is no option to bulk block several numbers simultaneously.
- Do blocked numbers stay blocked forever?
- Yes, a number remains blocked until you manually unblock it from your WhatsApp settings.
Blocking unknown numbers on WhatsApp is a straightforward process that can greatly improve your digital well-being. By staying vigilant and making full use of available privacy features, users can maintain a safer and distraction-free messaging environment.