Asked on 10 Oct 2020
Student credit cards often have inferior features and benefits as compared to normal credit cards. You could benefit from having different cards from different banks in order to take advantage of bank promotions. Some banks offer sign-up bonuses too for students from time to time, so do keep a lookout!
If privacy matters to you, you should know that all transactions by the supplementary cardholder can be seen by the main cardholder.
Instead, you can help your parents look through household expenses and optimize their spending! For example, if they are chasing miles, it would be good to separate spending by categories and spend on different cards, such as 4mpd on online purchases using Citi Rewards. The Milelion is a good place to start if you want to find out more.