The 24-hour window (Customer Care Window) is a Meta rule that governs what messages a business can send to a customer via the WhatsApp Business API without using templates.
If a customer messages a business, a 24-hour window opens: For 24 hours from the time of the customer’s last message, a business can send any free-form (session-based) messages—text, files, buttons, etc.—with no content restrictions and without needing to use pre-approved templates.
Once the 24 hours have elapsed and the customer has not messaged again, the window closes. To resume the conversation, the business must send the customer a template message (Template Message) that has been pre-approved by Meta.
The chat window opens only at the customer’s initiative—that is, when an incoming message is sent from the customer’s number to the business. This can be:
Important note: A business cannot open the chat first via the standard API. If a customer has never messaged the bot or received any messages from it before, the only way to start a conversation is to send them an approved template.
When using Coexistence mode (where a number operates simultaneously in the WhatsApp Business app on a phone and via the API), an additional option becomes available: an employee can message a customer first through the mobile app, and this counts as the start of a conversation—without the need to send an approved template.
This works because, in Coexistence mode, a message sent from a phone technically does not go through the API but rather through the regular WhatsApp app, to which the 24-hour window restriction on templates does not apply as strictly as it does to messages sent via the API. Thanks to this:
This is useful for scenarios where the first contact with a customer is personalized and non-automated, and using a template message would be excessive or less personal.