What's the problem with running business calls on a personal WhatsApp?
The account is tied to one phone number and one primary device, usually the owner's own mobile. That works fine for a sole trader, but as soon as a second person needs to answer as the business, there's no separate login for them, only a device linked to someone else's number.
WhatsApp Business registers to a phone number, and the free app treats that number's phone as the primary device. Up to four more devices can link to it, but WhatsApp's own help centre is explicit that the primary phone still has to log in at least once every 14 days, or the linked devices sign out. Whoever owns that phone number is, structurally, the account.
For a business of one, that's not a problem. It becomes one the moment a second person needs to answer as the business rather than as themselves. The free app has no separate login per person and no way to assign a chat to whoever is actually handling it (Meta Verified can add device access and chat assignment on top, where available). In practice, teams end up sharing one phone, or one person's number becomes the business's number by default, whether that was the plan or not.
A dedicated business number doesn't have that dependency. It can be issued fresh or ported from an existing line, and it isn't registered to any one person's mobile, so it survives someone being on leave, changing role or leaving the business entirely. Each person can still have their own login on the same number, which is the setup covered in shared number or individual numbers for a small team.
None of this means dropping WhatsApp. It's still a fine channel for quick, informal customer messages, and plenty of customers already have it open. The point is not to let it become the business's phone system by accident, just because it was the easiest thing to start with. For the fuller side-by-side, see Olatti vs WhatsApp Business.
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