Question:
Are there any ribit issues if I use my mothers credit card. the credit card company may charge interest and if I use it then my mom pays the bill with interest on my behalf. is that a problem?
Answer:
If you are paying the interest of your mothers credit card bill, yes that would be a problem, the same way it would be a problem to use any other persons credit card. If your mother is the one who pays the bills of your purchases, then it is permitted because it would the same as anytime she takes a loan on her credit card and pays the gentile company interest.
