WhatsApp has quietly become one of the most important customer interaction channels in the world. Meta CEO Mark Zuckerberg told investors in 2025 that WhatsApp now has more than 3 billion people using it every month, putting it in a small club of apps that have crossed that threshold alongside Facebook itself. In India—WhatsApp’s largest user region with over 500 million users— WhatsApp has become “a way of life,”, and in the United States, where messaging habits have historically favored SMS and iMessage, WhatsApp has crossed 100 million monthly active users, a milestone reported by outlets like Fortune and The Verge.
Against this backdrop, WhatsApp’s upcoming username feature and the introduction of Business‑Scoped User IDs (BSUIDs) are not minor API tweaks. They are structural changes in how identity works over one of the world’s primary customer channels. This article looks at why that matters, what actually changes for customers, and how it will impact the workflows and applications businesses have already built on top of WhatsApp.
What exactly is the technical change?
Until now, WhatsApp has been fundamentally phone‑number‑centric. To talk to a business, customers needed its number or a deep link; that same number showed up in webhook payloads, CRMs, and routing logic from the very first message.
WhatsApp is now moving toward a handle‑driven, privacy‑preserving model built on two pillars:
Usernames for people and businesses - Starting later this year, customers will be able to find and contact businesses via usernames (for example, @yourbrand), instead of relying on phone numbers. This makes discovery more intuitive and gives customers a way to interact without exposing their number up front.
Business‑Scoped User IDs (BSUIDs) - Under the hood, WhatsApp will issue a unique identifier for each user–business pair, known as a BSUID. The same person will have different BSUIDs for different businesses, and the ID is only meaningful within the scope of that business. Technically, the BSUID shows up in API payloads in a format like: whatsapp:CC.BSUID. CC represents a two-letter ISO country code, while the BSUID is an opaque identifier string. The inclusion of the country code in the BSUID can be beneficial in workflows where it serves as a decision-making factor.
When a customer messages your business via username and chooses not to share their phone number, your integration will typically see only this BSUID as the user identifier, not their underlying number.
How will this change affect the customer experience?
From a customer’s perspective, usernames and BSUIDs unlock three important shifts in how it feels to talk to a business on WhatsApp.
1. Safer, lower‑commitment first contact - Customers will be able to initiate a chat or even a call with a business using its username without immediately giving away their phone number. That matters in categories where sharing contact details has historically felt like a big step—banking, healthcare, financial advice, or personal services. Instead of “message this number and hope it’s really the brand,” the pattern becomes “tap this verified username and start a chat,” with the number staying hidden until the customer chooses otherwise.
2. Stronger, more consistent brand identity - Usernames let businesses present a clean, cross‑channel identity: the same or similar handle across WhatsApp, social, and the website, rather than a bare phone number that customers have to save in contacts. Combined with official business profiles and verification, this makes it easier for customers to recognize the real brand, which in turn helps combat impersonation and low‑grade fraud that thrives on look‑alike numbers.
3. Privacy by default, not by exception - With BSUIDs, the business only sees a scoped ID unless and until the customer chooses to share their number or other identifiers. This matches what users already expect from many digital services: they sign in with a phone or email, but external services see pseudonymous IDs rather than raw contact details.
What remains unchanged at a high level?
Even as identity shifts from phone‑centred to username‑plus‑BSUID, the fundamental expectations around consent and outbound messaging remain the same:
Businesses must still obtain a clear, affirmative opt‑in before sending marketing or other proactive messages over WhatsApp.
Users must be able to opt out easily, and those choices must be honored promptly.
Meta continues to track quality and complaint signals, and can restrict templates or accounts that misuse the channel (Ref: Meta Business Policy).
The deeper consent mechanics—how to unify permissions across phone numbers and BSUIDs, and how to avoid accidentally double‑sending campaigns—will be covered separately in Blog 2. For now, it is enough to say: usernames and BSUIDs do not loosen the consent rules; they just change what your systems see when a customer talks to you.
Preparing for these changes as a Customer Experience and Messaging Professional
Most current WhatsApp implementations rely on a quiet assumption: the inbound WhatsApp ID is the customer’s phone number. That single assumption drives a lot of behavior:
The first message triggers an instant CRM lookup keyed by phone number.
Routing engines can immediately detect whether this is a known customer and apply segmentation or priority rules.
Bots can start personalized flows from the very first turn of the conversation.
Usernames and BSUIDs break that assumption in important ways:
If a customer initiates via username and keeps their number hidden, the webhook your system receives may contain only a BSUID, with no phone number field populated.
Any code that expects from or wa_id to be a valid E.164 number will either fail validation or quietly store an opaque string in fields that were designed for numbers.
CRM lookups that depend solely on phone numbers will return nothing, even if the customer has transacted with you before under the same real‑world identity.
That pushes identity resolution out of the transport layer and into the conversation design. Instead of inferring who the customer is from a number you never asked them for, you now have to decide where and how you will explicitly establish identity inside the flow.
Self‑Service vs High‑Trust Flows in a BSUID‑First World
A practical way to think about BSUID‑first sessions is to separate inbound journeys into two broad categories.
1. Low‑risk, anonymous‑friendly experiences
These are flows you can safely run using BSUID as nothing more than a session key:
FAQs and knowledge‑base lookups.
Store finders, location queries, and general product discovery.
Early‑funnel qualification where you ask about needs and interests but do not expose account data.
In these contexts, it does not matter that you cannot immediately map the BSUID to a long‑term profile. The goal is to be helpful, set expectations, and decide whether there is a fit—without touching sensitive data.
2. High‑risk, identity‑dependent experiences
These are use cases where you cannot take action without knowing who you are dealing with:
Banking and financial services: balance checks, card controls, loan status updates, account‑linked offers.
Insurance: policy changes, claims progress, coverage details.
Healthcare: appointments tied to medical records, test results, personal health information.
In these flows, BSUID is not an identity; it is just a way to keep the chat tied to the right person once you have verified them. You will need an explicit identity step—often some combination of:
Asking for a phone number or account ID and verifying it.
Handing off to a secure web or app login and then confirming the link back into WhatsApp.
Using one‑time codes shown in a logged‑in experience that the user must echo in the chat.
For high‑trust sectors, the design challenge is to make these checks feel like safety features, not friction. Clear messaging (“we’re asking this to protect your account”) and tight flows are key.
How Existing Applications and Workflows Will Need to Change
Beyond the conceptual shifts, usernames and BSUIDs will force very concrete changes in the applications and workflows that sit on top of WhatsApp.
1. Evolving the identity model
Anywhere your systems currently store “WhatsApp ID” as a phone number, you will need to introduce BSUID as a first‑class identifier.
Many implementations will end up with a model where a single customer record can hold multiple WhatsApp identifiers: one or more phone numbers and one or more BSUIDs.
Internal services and routing rules should stop validating WhatsApp IDs as purely numeric; they must accept opaque strings like whatsapp:US.xxxxx.
2. Updating CRM and self‑service flows
Flows that depend on automatic CRM enrichment via phone number will need explicit identity collection steps when the number is not available in the first webhook.
“VIP” or “high‑value customer” routing that currently runs before any dialogue may need to move after you have either mapped the BSUID to a known profile or collected a trusted identifier.
For trust‑critical sectors, expect to add small but important steps to confirm identity before exposing personalized data or performing account actions.
3. Rethinking inbound abuse and spam controls
If you currently maintain blocklists of phone numbers associated with abuse, those lists will not catch bad actors who approach you on username‑only BSUIDs.
You will need to extend suppression and deprioritization logic to BSUIDs while acknowledging that usernames—and in some scenarios, the BSUIDs associated with them—can change over time.
The more robust strategy is to combine identifier‑based lists with behavioral signals (message velocity, complaint rate, abuse patterns) and to lean on WhatsApp’s native reporting and blocking features as your first line of defense.
4. Making journeys geo‑aware by default
Use the BSUID country prefix to start in the right language, show relevant disclosures, or quickly inform customers if you cannot legally or practically support them in their region.
For multi‑region brands, coordinate this with your legal and compliance teams so that default messages and flows reflect actual obligations and entitlements in each market.
Overall, this is more than a “just add a field” change. It touches data models, routing, self‑service design, spam controls, and geo handling across your stack.
Handled thoughtfully, usernames and BSUIDs will let you offer more privacy, clearer branding, and better‑designed journeys on WhatsApp. Treated as a background protocol change, they will quietly erode personalization, introduce routing gaps, and leave both customers and risk teams uneasy.
