If an end-user responds to one of your ads in the iOS or Android WhatsApp app by using a click to WhatsApp ad button, a customer service window is opened. If you respond to the end-user within that 24-hour customer service window, a 7 day Free Entry Point window is created.
Meta will waive its fees for any messages (including template messages and free form/service messages) you send to this end-user during the Free Entry Point window. Note that Sinch's fees will still apply to each message.
Click here for more information about the Sinch WhatsApp Business API.
