There are several reasons to add an authorized user to your credit card account. One reason is to help them establish a credit history. If the authorized user pays their bill on time and keeps their balance low, this will help them build a good credit score. Another reason to add an authorized user is to earn rewards points. If you have a rewards credit card, you can earn points for every purchase the authorized user makes. Finally, adding an authorized user can help you manage your finances better. If you have trouble keeping track of your spending, adding an authorized user can help you see where your money is going each month.