WhatsApp Business-Scoped User IDs (BSUID): what changes in 2026
A Business-Scoped User ID (BSUID) is a stable identifier Meta generates for every WhatsApp user–business pair, introduced alongside WhatsApp usernames in 2026. As users can hide their phone number behind a username, your systems key each contact on their BSUID instead of the raw number — and InfiQ handles that mapping for you as an official Meta Business Partner.
Business-Scoped User ID
IN.83412907● ● ●5029
Why BSUID exists — the usernames privacy change
Meta is introducing WhatsApp usernames in 2026 so people can chat with businesses without sharing their phone number. To keep business messaging working when the number is hidden, Meta assigns every user–business pair a stable Business-Scoped User ID (BSUID). It becomes the reliable way to recognise a returning customer and continue a conversation, even when all you ever see is a username.
What a BSUID looks like
The format is an ISO country code, a dot, then up to 128 alphanumeric characters — for example IN.83412907…5029. It is scoped to your business: the same person has a different BSUID with every business they message. It stays stable unless the user changes their phone number, in which case Meta sends a user_id_update webhook carrying both the old and the new ID so you can migrate your records.
Are you eligible?
A quick readiness check for the 2026 usernames change:
0 of 5 ready — tick the rest to confirm eligibility.
Set it up with InfiQ
Get BSUID-ready with InfiQ in five steps:
0 of 5 steps done
Start reading the business-scoped user ID from inbound webhooks as they appear from April 2026.
Save the BSUID alongside each customer record so a hidden phone number never breaks the thread.
When Meta sends a user_id_update webhook, migrate the old ID to the new BSUID automatically.
Switch outbound messages to target the BSUID wherever the customer's number is hidden behind a username.
InfiQ captures, stores, maps and migrates BSUIDs for you as an official Meta Business Partner.
What you need to do
Store the BSUID against each contact rather than relying on the raw phone number, handle the user_id_update webhook to migrate a contact when their ID changes, and be ready to address outbound messages by BSUID where the number is hidden. Tie your opt-in and consent records to the contact, not the number. On InfiQ this is handled for you — we capture, store, map and migrate BSUIDs behind the scenes.
Timeline
Business-scoped user IDs begin appearing in webhooks from around April 2026, and support for sending messages targeted to a BSUID follows from around May 2026 (providers cite a May–June 2026 cutover). The practical takeaway: start capturing and storing BSUIDs as soon as they appear so nothing breaks when numbers begin to hide behind usernames.
Frequently asked questions
What is a BSUID?+
Why is this changing?+
What does a BSUID look like?+
Is it the same as the phone number?+
When do I need to be ready?+
Does InfiQ handle BSUID for me?+
Still have questions?
Ask on WhatsAppGet BSUID-ready before the 2026 WhatsApp usernames rollout — talk to InfiQ.