You can send responses to user-initiated messages. You may respond to user messages with any type of message (including non-templated messages) within 24 hours of message receipt. This 24-hour period is known as the customer service window, or a customer care session. Non-templated messages and utility messages sent within a customer service window will not be charged.
Marketing and authentication template messages will be charged based on their category, regardless of whether they are sent within a customer service window. Note that, if sent outside of a customer service window, utility messages will also be charged.
For more information refer to the following WhatsApp article: WhatsApp Business Platform Messages Overview.
Learn more about how you can use the Sinch WhatsApp Business API to send messages easily and securely.
