About WhatsApp usernames

Learn how WhatsApp usernames and Business-Scoped User IDs (BSUIDs) work, and what they mean for your customers and your Klaviyo account.

Meta is introducing WhatsApp usernames to make it easier for customers and businesses to connect while giving customers more control over their privacy. Until now, starting a conversation with a business on WhatsApp required sharing a phone number. With usernames, customers can choose to start conversations without revealing their phone number, and businesses can reserve a username that customers can use to find them.

Businesses can begin reserving a WhatsApp username starting in June 2026. Beginning in July, Meta will gradually roll out WhatsApp usernames for businesses by country. As the rollout reaches each market, customers will be able to discover and message businesses using business usernames, and businesses will begin receiving messages from customers who use WhatsApp usernames. Klaviyo automatically supports these changes, so you do not need to update your WhatsApp setup or migrate existing data.

What's changing

WhatsApp usernames are optional for both customers and businesses.

Customers can create a unique username in the format @username and use it instead of sharing their phone number when they start a conversation with a business.

Businesses can reserve a unique username for their WhatsApp Business account. As Meta rolls out the feature by country, businesses become discoverable by their username, allowing customers to search for and message them directly in WhatsApp.

Customers who prefer to use their phone number can continue doing so. Usernames do not replace phone numbers; they provide another way for customers and businesses to connect.

When a customer starts a conversation using a username instead of a phone number, Meta assigns a Business-Scoped User ID (BSUID). Klaviyo uses this identifier to recognize the customer while helping protect their privacy.

About the BSUID

A Business-Scoped User ID (BSUID) identifies customers who contact your business using a WhatsApp username instead of a phone number.

The BSUID helps protect customer privacy while giving your business a consistent identifier for messaging.

Key details about the BSUID:

• It is created automatically when a customer starts a conversation using a WhatsApp username.
• Each business receives a different BSUID for the same customer, preventing businesses from identifying that customer across other brands.
• You do not need to configure or request a BSUID.
• A BSUID looks similar to US.13491208655302741918, with a two-letter country code followed by a unique identifier.

How Klaviyo uses the BSUID

You do not need to change your WhatsApp setup. Klaviyo automatically supports customers identified by either a phone number or a BSUID.

Klaviyo makes the BSUID available throughout the platform so you can use it alongside your existing customer data.

You can:

• View the BSUID on WhatsApp delivery events.
• Build segments using the BSUID field, just as you would with other event data.
• View the BSUID on a customer's profile alongside their other profile information.

What's changing and what's staying the same

Most of your WhatsApp workflows continue to work exactly as they do today. The primary differences are how customers discover your business and how some customers are identified when they message you.

What's changing

• You can reserve a WhatsApp username for your WhatsApp Business account beginning June 29, 2026.
• As Meta rolls out the feature by country, businesses become discoverable by their username, allowing customers to search for and message them directly in WhatsApp.
• As the rollout reaches your market, you begin receiving messages from customers who use WhatsApp usernames.
• Customers who message your business using a username may be identified by a Business-Scoped User ID (BSUID) instead of a phone number.
• Those customers appear in Klaviyo profiles and segments with their BSUID, giving you another identifier you can use for targeting and organization.

What's staying the same

• You continue sending WhatsApp messages the same way.
• Your templates, message types, and flows continue to work as they do today.
• The 24-hour conversation window and WhatsApp billing do not change.
• Existing phone numbers remain valid and continue working normally.

Rollout timeline

Meta is introducing support for WhatsApp usernames for businesses in phases.

As the rollout reaches your market, your business becomes discoverable by its WhatsApp username. You may also begin receiving messages from customers who use WhatsApp usernames and see Business-Scoped User IDs (BSUIDs) in Klaviyo.

Frequently asked questions

What happens if a customer never creates a username?

Nothing changes. You continue messaging that customer using their phone number. Usernames are optional, and customers can continue using phone numbers if they prefer.

If I reserve a business username today, can customers use it immediately?

Not yet. Reserving your username secures it for your business. Meta is gradually rolling out support for businesses to receive messages from customers who use usernames, so customers will be able to discover and message your business by username as the rollout reaches your markets.

Will I still see phone numbers for my customers?

Yes. Existing contacts, and customers who message you using their phone number, continue to display their phone number. Customers who contact you using a username may display only a BSUID.

Does changing a username change the BSUID?

No. Customers can change their WhatsApp username without changing their BSUID. The BSUID changes only if they change the phone number associated with their WhatsApp account.

Do I need to set anything up?

No. Klaviyo automatically supports customers who use WhatsApp usernames and surfaces the BSUID on WhatsApp delivery events and customer profiles. You do not need to configure anything before the rollout reaches your customers.