The 24-hour window is the line that separates what you can send freely from what requires a template. Most of the pricing model follows from it.
How it works
When a customer sends you a message, a 24-hour window opens. Inside it, you can reply with anything: free-form text, images, interactive messages, buttons, lists. No template, no approval, no pre-registration.
Every new inbound message from that customer resets the window to a fresh 24 hours. A conversation that runs over several days stays open the whole time, as long as the customer keeps replying.
When the window closes, free-form messaging stops. To reach that customer again you must send an approved template, which opens a new interaction and is billed under its own category.
What this means for your bill today
As of now, the window is also a billing boundary:
- Inbound messages: always free, however many arrive.
- Outbound inside the window: free-form replies are
servicemessages, andserviceis currently free. - Outbound outside the window: requires a template, billed as
marketing,utilityorauthentication.
That's why support-heavy businesses have had such cheap WhatsApp bills. A twenty-message support conversation costs nothing, as long as the customer opened it.
Vera Market
All 120,000 of their support replies happen inside the window, because the customer always opens a support conversation. All 120,000 are free.
All 150,000 order templates are sent outside any window (nobody writes in asking to be notified that their order shipped), so all 150,000 are billed.
The window isn't the same as a conversation
Older WhatsApp pricing documentation talks about 24-hour conversations as the billing unit: you paid once to open a conversation, then everything inside it was included. That model is gone. Pricing is now per message.
The window still exists and still governs what you're allowed to send. It no longer bundles a set of messages into a single charge. If you find a blog post describing conversation-based pricing, it predates the current model, and its arithmetic won't match your invoice.