WhatsApp usernames are coming. What happens to the phone numbers in your contact list

Ayesha Siddiqui runs operations for a pathology lab with three collection centres in Lucknow. Reports go out on WhatsApp, and the lab software finds each patient by mobile number. When a patient writes “report ready?”, the front desk types the number into the lab system, finds the visit, and sends the PDF.

That works because every WhatsApp message arrives with the sender’s number. For customers who adopt a WhatsApp username, it may stop arriving.

What WhatsApp has announced

On 29 June 2026 WhatsApp opened username reservations. Its announcement says usernames will roll out “gradually over the coming months” and that WhatsApp will tell people in the app “when they’re available in your country”. Once usernames launch, someone who has enabled one and messages a person or business for the first time “will no longer see your phone number”. There’s also an optional username key, which someone needs to know before they can message you by username.

Meta’s developer page on the change, last updated 15 September 2026, still says WhatsApp “will start rolling out usernames gradually in 2026”. As of early October 2026 we found no Meta date for India, and no statement that usernames are switched on for customers anywhere. Two things are certain: usernames are optional for users, and you can’t control which of your customers adopt one.

Businesses can have usernames too, reserved from 29 June 2026. A business username doesn’t hide your business number. Meta’s username API may refuse a business whose portfolio has too low a messaging limit, without saying what level is enough.

The BSUID, in plain terms

To keep messages flowing when there’s no phone number, Meta added a business-scoped user ID, or BSUID. It has appeared in every incoming message webhook since early April 2026, whether or not the customer has a username.

What matters about it:

• It starts with the customer’s two-letter country code and a full stop, then up to 128 letters and digits. For an Indian customer, that means it starts with IN..
• It’s unique to one pairing of your business portfolio and one customer. Another business sees a different BSUID for the same person, and so does your own second portfolio.
• It changes if the customer changes their phone number. Meta sends a system message with the old and new values when that happens.
• Since July 2026 you can send to a BSUID instead of a phone number, using any message type except one-tap, zero-tap and copy-code authentication templates, which still need the number.

Meta says supporting BSUIDs is mandatory for every provider and every business integrated directly with the Platform, and for click-to-WhatsApp advertisers. If you use a provider, this is mostly their job. But the contact records it lands in are yours.

When you’ll still see the phone number

Meta keeps sending a username adopter’s phone number in webhooks if any of these is true:

• your business number messaged or called their number in the last 30 days;
• their number messaged or called your business number in the last 30 days;
• they’re in your contact book.

The 30 days are counted per business number. If your sales number spoke to a customer last week, your support number won’t get their phone number unless it has spoken to them too.

The contact book is a Meta-hosted store, kept per business portfolio. Once it’s live for you, any message or call between one of your numbers and a customer’s phone number records their number and BSUID, and Meta uses it to keep the number in future webhooks. It only captures interactions after it starts. You can turn it off under Business settings in Meta Business Suite, but turning it off deletes what it has stored, and switching it back on doesn’t restore it.

The gap is the customer who went quiet. Meta’s own FAQ warns that an existing customer who writes after more than 30 days, and isn’t in your contact book, “may look like a new user thread to you”. For a lab, that’s the patient who last tested in March.

Customer	Has a username?	What your system receives
Regular, messaged this month	Either	Phone number and BSUID
In your contact book	Either	Phone number and BSUID
Quiet for 30+ days, not in contact book	No	Phone number and BSUID
Quiet for 30+ days, not in contact book	Yes	BSUID and username only
New customer	Yes	BSUID and username only

Asking for the number

Meta added a REQUEST_CONTACT_INFO button in early July 2026. You can put it on a utility or marketing template, or send it as an interactive message. Its label is fixed, “Share Contact Info”, shown in the customer’s own language. If the customer taps it, their number is shared in the chat and your system receives it.

It’s a request, not a right. Some customers chose a username precisely so businesses wouldn’t get their number. Ask only when you need it, and say why, such as matching a test report or arranging a home collection. If they don’t share it, your flow needs a second path, perhaps a booking ID or the patient’s name and date of visit.

What to change now

Most of this is quiet groundwork. It’s far easier while numbers and BSUIDs still arrive together.

1. Ask your provider two questions: do you store the BSUID on each contact, and can I see or export it? If the answer is no, that’s the first thing to fix.
2. Treat the BSUID as a second key on the contact, not a replacement. Ayesha’s lab keeps matching patients on mobile number, but every contact record also holds the BSUID from the most recent message.
3. Let systems outside WhatsApp, like lab software, a CRM or billing, accept a contact with no phone number. Meta’s FAQ says anything triggered off your CRM, campaigns included, needs to handle it.
4. Keep the BSUID current. Since it changes when a customer changes number, update it from the system message rather than creating a duplicate contact.
5. Record opt-ins against the person, not just a number. Meta’s opt-in policy requires that people agree to hear from you, and your record of that agreement should still find them when the next message carries only a BSUID. Our opt-in guide covers what to record.
6. Use one business portfolio for your WhatsApp numbers if you can. BSUIDs and the contact book are per portfolio, so splitting numbers across two portfolios splits your customers into two sets of IDs. Large groups can ask Meta about parent BSUIDs, which work across portfolios.
7. If you run click-to-WhatsApp ads, check your lead reporting. A lead with no phone number still needs to be counted.

The part that’s still open

Meta’s page says everything on it is “subject to change”, and its own dates have already moved: sending to a BSUID was first listed for May 2026 and arrived in July. The consumer launch date, and when India gets it, aren’t published. Re-read the business-scoped user IDs page once a month. Its changelog at the bottom shows what moved.

This week, pull ten recent contacts from your system and check whether each one has a BSUID stored. If none do, raise it with your provider before usernames reach India. The glossary has short definitions of BSUID and usernames, and our guide to customers stuck in staff phones covers getting every customer onto one business number first.