WhatsApp usernames and BSUIDs replace phone-keyed contacts

WhatsApp is rolling out usernames, and Meta now identifies users with a business-scoped user ID (BSUID). Webhooks for username users may omit the phone number, breaking integrations that key contacts by number. Supporting BSUIDs is required for all partners.

• A BSUID looks like US.13491208655302741918 and is scoped to a business portfolio
• BSUIDs appeared in webhooks in April 2026; username reservation opened June 29
• Phone numbers appear in webhooks only with contact in the last 30 days
• Supporting BSUIDs is required for all partners