Spouses often share financial responsibilities, ranging from joint checking accounts to mortgages and credit cards. However, many spouses who use each other's credit cards may not be allowed to do so. Whether your spouse is allowed to use your credit card depends on the nature of the card and the agreement you have with your credit card company. Always talk to a lawyer if you need legal advice about using a spouse's credit card.
One common way spouses obtain and use credit cards is by using a joint credit card account. Joint accounts are those where both spouses are listed as account holders and where each spouse has a duty to pay for debts incurred on the credit card regardless of which person made the purchase. Joint accounts allow either spouse to use the credit card freely and without permission of the other, and joint credit account information is included on both spouse's credit reports, according to the Federal Trade Commission.
An authorized user is someone who is permitted to use another person's credit card. For example, man who has a credit card prior to getting married can, after marriage, add his wife as an authorized use of his account. In these situations, it is perfectly acceptable for the wife to use the credit card. However, because the wife is not an account holder, only the husband is held responsible for paying any debts incurred on the card.
Unless you are an authorized user or an account holder, you do not have the right to use your spouse's credit card. However, spouses commonly use the their partner's credit cards to make transactions without running into trouble because the spouses share a last name. Merchants do not have to accept such transactions but often do because of the presumption that the spouses have a joint account or that the use has implied authority to use it.
Card holders are not responsible for the fraudulent activity of others, and the unauthorized use of a credit card can be illegal. If your spouse has permission to use your card, such transactions are generally not considered illegal, though it is up to the government to determine this. If, for example, your spouse uses your credit card while you are going through a divorce and she is not an authorized user or joint account holder and knows that she is not allowed to use the card, such use may constitute a crime.