Under Federal law, if your credit card (or your automatic banking card) is used without your authorization and before you report it missing, you can be held liable for the actual amount or up to $50 per card. If you report the loss before the card is used, the card issuer cannot hold you responsible for any unauthorized charges. You are not responsible for any charges made after you notify the card issuer of the loss or theft of the card.
Be sure you know how to notify your credit card issuers in case you find your cards missing and be sure to follow your issuer's directions for reporting unauthorized charges. If you are considering using a credit card protection service, which for a fee promises to contact all you credit card companies for you in the case of loss or theft, be sure to read the contract carefully to check the company's obligations and any liability on your part should the company fail to notify card issuers.