The recipient of your Viber business messages must provide their consent (opt-in) before you can send them any message and you must retain proof of receipt of such consent.
Business Messages that are sent to users without such users’ consent will be considered spam messages and the Partner and its applicable Business(es) will be subjected to liquidated damages, as further specified in the Business Messaging agreement.
For sessions message type, the user must initiate the conversation with a Business by using Viber’s URL scheme. A user who has initiated the conversation will be considered as opted-in for future messages until he revokes such opt-in or unsubscribes.
Viber pro-actively monitors and blocks spammers from sending Business Messages.
Users will be able to block the Business from sending Business Messages at any stage.
Learn more about Viber Business Messaging at Sinch.