Session messages are the replies a business sends while a customer service window is open, that is, in the 24 hours after the customer last wrote or called. They can contain any supported content: text, images, documents, interactive buttons or lists.
They contrast with template messages, which are required to start a conversation or to message a customer once the 24-hour window has closed.
On pricing, Meta did not charge for service messages between November 1, 2024 and September 30, 2026. Since October 1, 2026, each business phone number gets 1,000 free service messages per month, which do not roll over, and Meta charges from the 1,001st at the rate published for the recipient's market. Replies sent in a free entry point window, after a click on an ad that clicks to WhatsApp, remain free.
Session messages are central to support and conversational selling. In Kanal, they are sent from a team inbox or by the AI chatbot, and the WhatsApp Business pricing guide details what each message costs.