Utility messages are service-related notifications such as booking confirmations, payment receipts, or account updates. On the WhatsApp Business API, these messages must be sent using pre-approved message templates, especially when reaching out to customers outside the 24-hour customer service window. Utility messages are non-promotional and are designed to provide important, timely information related to a customer’s existing account, transaction, or service. If a customer initiates a conversation, you can reply freely within the 24-hour window; however, to start a new conversation or send updates after this period, a utility message template is required.