Block users

Block one or more WhatsApp users on this number. Blocked users cannot message your number or see that you are online, and your sends to them return an error.

Meta constraints, surfaced per-user in failed (the request itself still succeeds for the rest of the batch):

• Only users who messaged your business within the last 24 hours can be blocked (failures outside the window report "Re-engagement required").
• Up to 1,000 users per request; the blocklist caps at 64,000.
• Other WhatsApp Business accounts cannot be blocked.