To use the WhatsApp Business API, businesses need to undergo a verification process. This helps ensure that only legitimate businesses can access the API, enhancing user trust and security.

The API supports different message types, including Session Messages for real-time interactions, Template Messages for predefined content like order confirmations, and HSM (Highly Structured Messages) for transactional messages. Each message type has its specific use case and approval process.

Users must opt-in to receive messages from a business on WhatsApp. Additionally, businesses need to provide an opt-out mechanism, allowing users to stop receiving messages at any time. This ensures compliance with user preferences and privacy regulations.

Businesses using the WhatsApp Business API must adhere to WhatsApp's policies. This includes guidelines on message content, frequency, and interactions to maintain a positive user experience. Violating these policies may result in restrictions or account suspension.

Access to the WhatsApp Business API is not open to all businesses by default. Interested businesses need to apply for access, and approval is granted based on WhatsApp's criteria. Additionally, the API has associated costs, which may include message fees. Pricing details can be obtained directly from WhatsApp.