If your credit or debit card is lost or stolen, report it to your card issuer right away. When you timely report it, your liability for fraudulent charges is limited by law. For lost or stolen credit cards, the Fair Credit Billing Act caps your maximum liability for unauthorized charges of your credit card at $50, and many times your liability is even zero. When it comes to debit card, though, your liability under federal law for unauthorized charges depends on how quickly you report the loss. Under the Electronic Funds Transfer Act, if you report a debit card missing before it’s used without your permission, the card issuer cannot hold you responsible for any unauthorized transfers. If unauthorized use occurs before you report it, your liability under federal law depends on how quickly you report the loss. However, state law may provide you with greater liability protection. If you do find unauthorized charges on your account, you must sign an affidavit that the charges are indeed fraudulent.