The 24-hour window: when you can type, and when you need a template
Meta’s customer-service window, the timer on the conversation, what the composer does when it closes, and how chats from click-to-WhatsApp ads differ.
Updated 29 October 2026
On the Cloud API, a customer’s message opens a 24-hour window in which you can send anything: text, photos, documents, voice notes. The timer on the conversation counts that window down. Each new message from the customer restarts it.
When the window has closed
The composer shows "Messaging Window Expired" with the line "The 24-hour window has closed. Use a template to re-engage." and a "USE TEMPLATE" button. The text box reads "Window closed" and attachments are disabled. Press the button (or open the paperclip menu and choose "Template message"), pick an approved template and send it. When the customer replies, the window opens again and you can type freely.
Chats that started from an ad
A conversation that began from a click-to-WhatsApp ad carries an "AD" badge. Reply within 24 hours of the first message and Meta opens its free entry-point window; the conversation then shows until when messages are free.