Summarize:

When you add someone to your credit card account, they are able to legally make charges using your card. Obviously, granting another person access to your finances is a major decision so you should know the pros and cons before beginning the process.   Adding someone to your credit card account has many advantages. If someone cannot apply for a credit card on their own due to poor financial history, it may enable them to build a credit score depending on the credit card issuer or help them learn how to manage money if they are paying you back each month. You can make sure someone has money available in the event of an emergency. Having one credit card account is often more convenient than creating multiple ones. Adding someone to your credit card has its drawbacks as well. There is an added liability, as you're legally responsible for all actions an authorized user takes. Any missed payments or credit score damages affect the both of you. Shared accounts have also lead to strained relationships between users, as blame comes into play if there are issues with payments. When you add someone to your credit card, they're either a joint account holder or an authorized user. The responsibilities and rights of this person change greatly depending on their status.   An authorized user is entitled to use the credit card issued to the card's holder but have no financial responsibility when it comes to paying back any accrued loans.  Joint account holders share ownership of the account and have as much liability when it comes to repaying the debt as the original card holder.  You must make a decision, depending on the financial situation of both parties involved, whether the person you're adding will be a joint account holder or an authorized user. Many people wonder, when adding someone to their credit card, how and if this action will affect your credit score. This is information you should understand before making any decisions.   Credit reports generally don't supply information on authorized users. Adding a user in and of itself should not affect your credit score. However, you are responsible for any charges this person makes. If the new authorized user abuses their privileges, you could end up with large debts you are not able to pay. This will affect your score. The new user's credit score will actually be affected more directly. If the credit card issuer reports authorized users, the account will appear on their credit report and their credit score can change for better or for worse depending on your financial history. When you add a joint account holder, both parties will appear on each individual's credit report. Much like adding an authorized user, this will not affect your credit score in and of itself. However, a joint account holder cannot be easily removed from the account if there are outstanding charges. Your credit report might be affected more severely due to the potential longevity of any damage done.
Know the pros and cons of adding an authorized user. Distinguish between an authorized user and a joint account holder. Know the effect on your credit score.