WhatsApp Business Platform charges businesses for every conversation depending on the intent of the business and the customer's country code.
A conversation is defined as a 24-hour session regardless of the count of messages exchanged between the customer and the business.
The intent of the Business conversation is categorized into 4 types:
the intent of the Business is to respond to any user-initiated conversations.
Business Initiated Conversations where the intent is to notify the customer about a given transaction, including post-purchase notifications and recurring billing statements to customers who have opted in.
Business Initiated Conversations where the intent is to authenticate users with one-time passcodes.
Business Initiated Conversations where the intent is to increase sales through promotions or offers, informational updates. Any conversation that does not qualify as utility or authentication is a marketing conversation.
WhatsApp Business Platform offers also Free conversations
1000 free service conversations every month.
Businesses can’t initiate a new conversation unless they get an approval on the template message content as per the assigned category.
Conversation charges will be based on template category. When a template is delivered, it opens a new conversation of that category and incurs the charge of that conversation category, unless the template is delivered during an open conversation of that category. For example, if a utility conversation is open and a marketing template is delivered within that open conversation, a new, separate marketing conversation is opened and marketing conversation charge is initiated.
However, sending multiple templates of the same category within an open conversation will not incur additional charges. For example, a business can send multiple utility templates in an open utility conversation with no additional charges.
Service conversations will still only be initiated when no other conversation window is open and a business responds to a user with a free form message within the 24-hour customer service window. If a business replies to a user with a template message or sends a template message in an open service conversation, this opens a new conversation based on the template category.
The exception to this is free entry point conversations. During the free window, businesses can send multiple templates of different categories, and no new conversation will be opened. For more information