What is an unauthorized use of a credit card?
Generally, unauthorized use is the use of a credit card by a person who does not have the right to use the card.
For example, if you lose your card and someone finds it and uses it, that would be an unauthorized use.
However, if you give your card to someone to use, you have authorized the use. If the person uses the card for a different purpose, that may still be considered an authorized use. You would still be responsible for the charge, until you notify your card issuer that the person is no longer authorized to use the card. In that case, the card company may issue you a new credit card.