What is the 24-hour window
The 24-hour window opens when a customer sends a message to the business number and closes 24 hours later. During this window, you can send free messages (without approved template) to the customer.
Strategies to maximize the window
For customer support use cases, all communication happens inside the window. For proactive use cases, you must use templates.
Costs inside and outside the window
Service conversations (customer opens) are free up to 1,000 per month. Marketing, utility and authentication conversations have a per-conversation cost.