Service SMS include two SMS categories – Implicit and Explicit. Service Implicit can only be used for sending SMS such as OTPs and alerts to your registered users, whereas Service Explicit can be used for sending promotional messages to existing customers after receiving their consent.
Promotional SMS is used for sending any offers or promotions to new and existing customers. Messages can be sent between 9 AM and 9 PM only.
Transactional route can only be used by Banks to send OTPs and alerts.