What is the difference between Dedicated Long-Code and Shared Long-code
Shared Long-Code is the common number for a group of people. For MSG91 the shared Long-Code is 9229224424/6262642222. Using this number will be free of cost, you will be charged only for the incoming SMS. Incoming SMS is differentiated by keyword, and hence your keyword must be unique.
P.S. Everything you want to know about Long Code Service