Each new message or call from the customer resets the timer to 24 hours. Inside the window, the business can answer with any supported content, such as text, images, documents or interactive buttons, without a pre-approved template. Meta calls these replies service messages.
When 24 hours pass without a customer message, the window closes. To write to that customer again, the business must use an approved template, and the customer must have opted in.
The window also matters for cost. Since October 1, 2026, Meta charges for service messages after a free tier of 1,000 service messages per business phone number per month, and for utility templates sent inside the window. If the customer arrived through an ad that clicks to WhatsApp and the business replies within the window, a free entry point window opens instead and may stay open for up to 7 days.
Automation is allowed inside the window, provided customers have a clear path to a human. In Kanal, replies are sent from a team inbox or by the AI chatbot, which answers from the store's catalog and order data.
