If someone steals your MasterCard or fraudulently misuses your card number, you may no longer be liable for the first $50 in losses. MasterCard International Inc. announced that its customers will have "zero dollar liability" for fraudulent use of their credit or debit cards, even if they don't report the problem to their banks within 24 hours. Elimination of the 24-hour reporting requirement applies to all U.S.-issued MasterCard credit and debit cards and all types of purchases, including those over the Internet, according to MasterCard, which is based in Purchase, N.Y. The move by the nation's second-largest credit card system follows similar action by Visa, the nation's biggest card issuer. Visa, based in Foster City, Calif., announced earlier this year that it was eliminating its requirement that misuse of a card be reported within two days. In the past, MasterCard required fraud, theft or unauthorized use of its cards to be reported within 24 hours of discovery. If that didn't happen, customers could be held liable for up to $50 of the losses. MasterCard said that to qualify for exemption from the $50 liability, a cardholder must not have reported two or more incidents of unauthorized use in the preceding year and must have an account "in good standing."