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Can I use another person's credit card to purchase a subscription?
While deviantART users are more than welcome to purchase a subscripton with another person's credit card, you MUST have the permission of the credit card holder to do so.
Any unauthorized purchases made for a deviantART account will be treated as credit card fraud and the account responsible for the transaction will be banned without question.
In other words, if you are going to use your parents'/friends'/whoever's credit card, make sure they know the charge is coming so that they do not dispute the charge.
Unauthorized usage of another person's credit card is illegal, immoral, and just plain wrong.