Do I need the WhatsApp Business API or is the free Business app enough?

The Business app is a phone app with business features added: a profile with address and hours, a catalogue, quick replies, labels, greeting and away messages, and broadcast lists. It runs on one phone, with a few linked devices such as a laptop at the counter. It costs nothing, and it handles a surprising amount of volume if the person replying is organised. A bakery in Satellite Town or a tutor in G-11 rarely outgrows it.

The API, which Meta calls the WhatsApp Business Platform, is not an app at all. It is a connection that a software provider plugs into, and you then use that provider's inbox, chatbot builder or your own system. It gives you a shared inbox where five agents can work one number, assignment of chats to named staff, chatbot flows, and template messages such as order confirmations and appointment reminders sent automatically. In exchange you pay the provider, you pay Meta for template messages, and outbound messages must use templates Meta has approved.

A simple test: if one or two people can answer every chat within a reasonable time and nobody is asking 'who replied to this customer?', stay on the app and get it properly organised first. If chats are being missed because people are passing one phone around, or you are sending the same status update by hand dozens of times a day, the API starts to pay for itself.

The move is not one-way in your head but it is a real migration. Historically a number registered on the API could not stay on the phone app; Meta has since introduced a coexistence option through some providers that lets one number use both. Ask your provider which setup they support before you commit.