Really want to create a letter that requesting for the data card approval,you have.... 0. 0. If you really want to create a letter that requesting for the data card approval,you have to indicate in your letter what are the purpose of this letter to you,importance of having the data card.hen you have to indicate also when you needed this approval.You have to make sure that you can composed a letter that convinced her/him about this application. Sample letter below that will guide you on how to do your own pattern. Name of the Company.