Block a contact on a specific WhatsApp number to stop messages in both directions on that number. Other WhatsApp numbers in your workspace aren't affected.

How blocking works

You can block contacts when your team needs to stop unwanted or inappropriate conversations on a specific WhatsApp number. For example, you might block a contact who repeatedly sends spam or abusive messages, or when your team no longer wants to communicate with them through a particular number.

Blocking applies to each WhatsApp number separately. When you block a contact on a number:

• The contact can't message you on that WhatsApp number.
• Your team can't message the contact from that WhatsApp number.
• Other WhatsApp numbers in your workspace are not affected.

Blocking only applies to the WhatsApp number you select. The contact can still message your other connected WhatsApp numbers unless you block them there too.

Before you start

Before blocking a contact, make sure:

• You have a connected WhatsApp Cloud API number.
• You have permission to handle conversations on the WhatsApp number. If you don't, you'll see You don't have permission to block or unblock contacts on this WhatsApp number.
• The contact has messaged the WhatsApp number within the last 24 hours.

You can only block a contact on WhatsApp numbers they have messaged within the last 24 hours. WhatsApp makes the final decision when the block request is submitted.

Block a contact from Inbox

You can block a contact directly from their conversation in Inbox.

Step 1: Open the conversation menu

1. Click on the  icon on the left navigation bar to go to the Inbox
2. Open the contact's conversation
3. Check that the WhatsApp number you want to manage is selected in the message composer.
4. Open the  menu at the top right of the conversation.
5. Select “Block contact on WhatsApp”.

Step 2: Choose the WhatsApp numbers

In the Block contact on WhatsApp dialog, select one of the following options:

• All available WhatsApp numbers (n): Blocks the contact on all WhatsApp numbers that are currently eligible for blocking. 
• Specific WhatsApp numbers: Lets you choose which eligible WhatsApp numbers to block the contact on.
  
  • If you select Specific WhatsApp numbers, the list also shows numbers that aren't currently available for blocking. These numbers can't be selected, and the reason is shown below the number.

You might see:

• No messages in the last 24 hours: The contact hasn't messaged this number within the last 24 hours, so it can't be selected.
• Already blocked: The contact is already blocked on this number.
• Recently used: This is the WhatsApp number most recently used in the conversation.

If no WhatsApp numbers are available, you can't block the contact until they send a new message to one of your numbers.

Step 3: Confirm

1. Review the numbers you've selected.
2. Click “Block”

The number shown on the button updates based on how many WhatsApp numbers you've selected.

Once blocked, the contact can't message you on the selected numbers, and your team can't message them from those numbers. Other WhatsApp numbers aren't affected.

View blocked contacts

The WhatsApp blocked contacts page lets you review contacts blocked on your connected WhatsApp numbers and unblock them when needed.

Access the WhatsApp blocked contacts page

You can access the page from “Contacts” or directly from a WhatsApp number in “Channels”.

From the Contacts page

To access the WhatsApp blocked contacts page from the Contacts page:

1. Click on the  icon on the left navigation bar to go to the “Contacts” page
2. You will find “WhatsApp blocked contacts” group on the left-sided panel
   
3. Under WhatsApp blocked contacts, select:
   • All WhatsApp numbers to view blocked contacts across your WhatsApp numbers.
   • A specific WhatsApp number to view contacts blocked on that number.

From the Channels page

To access the WhatsApp blocked contacts page from the Channels page:

1. Click on the  icon on the left navigation bar to go to “Channels” page
2. On the left-sided panel, click “WhatsApp Cloud API”
3. Find the WhatsApp number you want to review.
4. Open the  menu next to the number.
5. Select “View blocked contacts list”.

Review blocked contacts

When viewing All WhatsApp numbers, contacts are grouped by WhatsApp number. The number beside each WhatsApp number shows how many blocked contacts it contains.

You can also use the WhatsApp number filter at the top of the page to view a specific number.

For each blocked contact, the page shows:

If Outside SleekFlow appears under Blocked by, the block was created outside SleekFlow. You can still unblock the contact from this page.

Search and refresh blocked contacts

Use the search bar at the top of the page to find a contact by name, phone number, or business-scoped user ID (BSUID). Select “Load more” to load additional contacts, then search again.

Select “Refresh” to reload the blocked contacts list.

Unblock a contact

Unblocking a contact removes the block from the selected WhatsApp number only.

Unblock from the WhatsApp blocked contacts page

1. Go to the “Access the WhatsApp blocked contacts” page
2. Find the contact and WhatsApp number you want to unblock.
3. Select “Unblock”.
4. Review the Unblock contact on WhatsApp confirmation dialog.
   
5. Select Unblock to confirm.

Once unblocked, the contact can message you again on that WhatsApp number.

Unblock from Inbox

You can also unblock a contact directly from their conversation.

On a blocked WhatsApp number, either:

• Select Unblock in the blocked composer notice.
  
• Open the conversation menu and select Unblock contact on WhatsApp.

In the dialog, choose:

• All blocked WhatsApp numbers (n) to unblock the contact from all applicable numbers.
• Specific WhatsApp numbers to choose individual numbers.

Then select “Unblock”.

The Unblock results screen shows whether the unblock request succeeded for each selected number.

If SleekFlow can't confirm the block status for a number, you can still try to unblock the contact on that number.

If you want to block the contact again later, they must have messaged that WhatsApp number within the last 24 hours.

What happens after you block a contact

Blocking applies to the specific WhatsApp number you selected. It does not remove the contact or their conversation from SleekFlow.

Inbox

When you open a conversation or switch the WhatsApp number in the message composer, SleekFlow checks whether the contact is blocked on that number.

• If the contact is blocked, you won't be able to send messages from that WhatsApp number. You can select “Unblock” to remove the block.
• If the contact isn't blocked on the selected number, you can continue messaging them as usual.
• Blocking a contact does not remove their conversation from the Inbox.

Broadcasts and Flow Builder

If a Broadcast or Flow Builder action tries to send a message from a WhatsApp number where the contact is blocked, the message will fail.

You can see the failed send and its reason in:

• The Inbox conversation
• Broadcast message details
• The Flow Builder run log

Troubleshooting