WhatsApp: How to Block Unknown Numbers

To block an unknown number on WhatsApp, open the chat from the unknown sender, tap the phone number at the top of the screen, scroll down, and tap “Block.� This stops messages, calls, and status updates from that number, and the sender is not notified that you blocked them.

Why You Might Need to Block Unknown Numbers

Unknown numbers reach you on WhatsApp through several channels. Someone may have your phone number from a data leak, a shared group, or a business directory. Scammers and spammers frequently use WhatsApp because it offers end-to-end encryption, free international messaging, and the ability to send media files that can carry malicious links. Common unwanted messages include phishing attempts that impersonate banks or delivery services, “free gift� scams, and unsolicited marketing blasts. Blocking is the most direct way to stop these messages, and unlike leaving a group or changing your privacy settings, it is permanent and specific to that one sender.

How Blocking Works on WhatsApp

When you block a number, WhatsApp immediately stops delivering that person’s messages and calls to you. The blocked sender does not see a “blocked� notification, but their messages will show only one gray check mark (sent, not delivered) instead of two. If they call you, the call will not ring on your device. You also stop seeing their profile photo, last seen status, and online status. The block is two-way: you can no longer see their updates, and they cannot see yours. The blocked contact remains in your chat list unless you delete the chat, and you can unblock them at any time from the same settings screen.

Step-by-Step: Blocking from a Chat

This is the most common method and works on both Android and iPhone. The menu names are slightly different, but the flow is the same.

Open WhatsApp and go to the chat from the unknown number.
Tap the phone number or contact name at the top of the screen to open the contact info page.
Scroll to the bottom of the page.
Tap “Block� (Android) or “Block This Contact� (iPhone).
Confirm by tapping “Block� in the pop-up dialog.

If the unknown number has not messaged you yet but you want to preemptively block it, you can save the number to your contacts, then use the same steps. Alternatively, you can block from the chat list by long-pressing the chat (Android) or swiping left (iPhone) and selecting “More� then “Block.�

Blocking Calls from Unknown Numbers

If the unknown number is calling you but has not sent a message, you can block it directly from the call log. Open the Calls tab in WhatsApp, find the missed or received call from the unknown number, tap it, and then tap the block icon (a circle with a slash) at the bottom of the screen. Confirm the block. This prevents future calls from that number. Note that blocking a number on WhatsApp does not block that number from calling your regular cellular line; those are separate systems.

What to Do If You Cannot Block the Number

Occasionally you may not see the Block option. This usually happens for one of three reasons:

The chat is from a group: If the message came from a group, you are seeing the sender’s profile, but the block option is still there—just scroll further down. If you want to stop the group itself, open the group info and select “Exit Group� or “Mute.�
The number is not saved as a contact: WhatsApp still shows the Block option for unsaved numbers. If it does not, restart the app and try again.
You are using an outdated version: Update WhatsApp from your app store, as older versions may have different menu layouts.

If the Block button still does not appear, report the number to WhatsApp instead. Open the chat, tap the three-dot menu (Android) or the contact name (iPhone), select “More,� then “Report.� Reporting sends the last few messages to WhatsApp for review and automatically blocks the sender.

Privacy Settings That Reduce Unknown Messages

Blocking stops individual senders, but you can also reduce how many unknown numbers reach you in the first place. WhatsApp has a few privacy controls that help:

Last seen and online: Set to “Nobody� or “My Contacts� so strangers cannot see when you are active.
Profile photo and About: Set to “My Contacts� so unknown numbers see a blank profile.
Status: Set to “My Contacts� to prevent strangers from viewing your status updates.
Groups: Change “Who can add me to groups� to “My Contacts� or “My Contacts Except� to avoid being added to spam groups.

These settings are found under Settings > Account > Privacy. They do not stop direct messages from unknown numbers, but they make your account less visible to people who scrape numbers or search for active users.

Unblocking and Deleting Chats

If you blocked someone by mistake or later decide to unblock them, go to Settings > Account > Privacy > Blocked Contacts. You will see a list of every number you have blocked. Tap “Edit� (iPhone) or the pencil icon (Android), then tap the red minus sign next to the number and confirm. Unblocking does not restore old messages; if you deleted the chat, you will need the sender to message you again. To delete a chat with a blocked contact, swipe left on the chat (iPhone) or long-press it (Android) and select “Delete.� Deleting the chat does not unblock the contact.

Frequently Asked Questions

Will the blocked person know they are blocked? No, WhatsApp does not send a notification. However, they may notice that their messages show only one check mark and that your profile photo and last seen are no longer visible to them. If they are technically savvy, they may infer the block.

Can a blocked number still see my profile picture? No. When you block someone, they lose access to your profile photo, About text, last seen, and online status. Your status updates are also hidden from them.

Does blocking on WhatsApp block regular SMS and phone calls? No. WhatsApp blocking only affects communication within the WhatsApp app. The number can still call or text your regular cellular number. To block that, use your phone’s built-in call blocking or your carrier’s spam blocking feature.

What happens to messages from a blocked number? The messages are never delivered to your phone. They remain on WhatsApp’s servers, but you will not see them. If you unblock the number later, those old messages will not appear retroactively.

Can I block a number that has not messaged me yet? Yes. Save the number to your contacts, then go to Settings > Account > Privacy > Blocked Contacts, tap “Add New,� and select the contact. You can block any number before they ever contact you.

Is blocking the same as reporting? No. Blocking simply stops communication. Reporting sends the chat history to WhatsApp for review and also blocks the sender. Use reporting for spam, scams, or harassment, because it helps WhatsApp take action against the account.

General steps for current mainstream versions; menus can differ by device and version. See the disclaimer or report an error.

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