Deletes the Meta contact book entry that associates a WhatsApp business phone number with a customer's WhatsApp Business-scoped user ID (BSUID).

Only standard BSUIDs such as US.11815799212886844830 are supported. Parent BSUIDs such as US.ENT.11815799212886844830 are not supported. The BSUID must be scoped to the same Meta business portfolio as the phone number. The specified WABA must belong to the authenticated YCloud account and be available, and the phone number must be bound to that WABA in YCloud. Use the YCloud account API key in the X-API-Key header. Developer App API keys are not supported and return HTTP 403.

An HTTP 200 response always has success=true. deleted=true means Meta reports that it deleted a matching contact book entry. deleted=false means Meta processed the request but found no matching entry to delete. This operation does not delete or modify YCloud Contact, message, or BSUID business records, and it does not bypass Meta's 30-day caching behavior. A later WhatsApp interaction between the same business phone number and customer may cause Meta to create the entry again.