What is the WhatsApp 24-hour rule?

A conversation includes all messages delivered in a 24 hour session. WhatsApp has two different types of conversations:

Note: This doesn’t apply to business hours. The 24-hour rule is exactly 24 hours from the time a user reaches out via WhatsApp. 

• User-initiated: A conversation that starts in response to a user message. Whenever you reply to a user within the 24-hour customer service window, that message is associated with a user-initiated conversation. You can send free-form messages within this 24-hour customer service window.
• Business-initiated: A conversation that starts from a business sending a user a message outside the 24-hour customer service window. Messages that initiate a business-initiated conversation require a message template. Message templates are currently in development.

Businesses and users can exchange any number of messages, including template messages, within a 24 hour conversation session. Each 24 hour session results in a single conversation.

After a user messages your business, a 24-hour timer starts. At hour 25, you can no longer respond to a user’s message. Timeliness and prompt replies are imperative during the beta as you can only respond during the 24-hour period.