WhatsApp Business API explained: what it is, what it costs and when you need it
· Inboxi Team
The difference between the WhatsApp Business app and the API, how per message pricing works, and how to connect a number in a few minutes.
The WhatsApp Business app is fine for one person and one phone. The API is what you need the moment two people answer the same number, an AI agent joins, or you want conversations to land in a shared inbox with your other channels.
The app and the API are different products
The app is free and you install it on a phone. It has a catalogue, greeting messages and away messages. The API has no app of its own. You reach it through a platform like Inboxi, and that is what gives you several team members on one number, automation and integrations with your store.
What it costs
Since July 2025 Meta has charged per delivered message, not per conversation. The price depends on the message type (marketing, utility, authentication or service) and on the country of the person receiving it. Messages customers send you are free, and the first 1,000 service replies each month are free for each number. You usually pay a platform on top of that.
The 24 hour window
When a customer writes to you, you have 24 hours to reply freely, and each new message from them restarts the clock. After that you can only reach them with a template Meta has approved. This one rule shapes most of how businesses use WhatsApp, and it is why answering quickly matters so much.
Connecting a number
You sign in through Meta's own window, verify the business, choose a number and get the display name approved. The WhatsApp account stays in your own Meta business portfolio, so you are not locked in to any one platform.
When you do not need it yet
If you get a few chats a day and answer them yourself, stay on the free app. Move when chats arrive after hours, when more than one person needs to reply, or when you want to send order updates automatically.