A Transactional SMS can be defined as an SMS that helps to convey important and mostly confidential data like PNR status, current bank parity etc. It has no limited time to send messages. Moreover, it does not contain any promotional message to promote any product or service, which is often done in promotional SMS. The optimum use of transactional SMS is done by banks, hospitals, railways and airlines, e-ticketing etc. Also, these messages can be sent by schools and other educational institutes in order to convey important messages to parents without containing any promotional tone. The messages are usually approved or opted-in by the recipients.