If you lose your credit card, find that it's blocked, or discover that unauthorized charges are being made while you're out of the country, the major cards like Visa or MasterCard have toll-free numbers you can call to straighten things out, get a replacement card, etc. Go to their websites (like http://www.visa.com or http://www.mastercard.com) and click on the options for reporting lost cards to get to a list of their toll-free numbers in other countries. For Brazil and Argentina, the numbers are the following. I strongly suggest writing them down and having them with you, along with your passport number and other vital info, in case of loss or theft. VISA: Argentina: 0800-666-0171 Brazil: 0800-891-3680 MASTERCARD: Argentina: 0800-555-0507 Brazil: 0800-891-3294 CITIBANK DEBIT CARDS: Whatever their other drawbacks, Citibank is a good choice for world travelers. Few problems using their ATM machines in Brazil or other countries to withdraw cash from your U.S. account. I've never had a problem using my debit card in Brazil (either fraud or just being blocked for suspicion of fraud) but if you do run into problems, or need to contact Citibank back in the U.S. for any other problem, their toll-free number from Brazil is 0800-891-0460. From other countries you can call collect to (210) 677-0065. However, there are toll-free direct numbers from other countries besides Brazil, which will be easier to use than trying to make a collect call. If you are traveling to another country where you'll be using your debit card, call the Customer Service number 1-800-627-3999 while you're in the U.S. and ask for their toll-free numbers from the countries you'll be visiting. If you do need to call collect, use AT&T's local USADirect access number. Ignore the first prompt. Wait for the second one, which will ask you to say "collect," and then ask for your name. DON'T HANG UP if the automated system doesn't complete the call for you because you get a voice mail system. Stay on the line and an operator will come on and complete the call. OTHER BANK DEBIT CARDS: Contact your bank before you travel to find out if they have toll-free numbers, or numbers you can call collect back in your home country in case of problems. If they don't, but your card has a MasterCard or Visa logo, you can try calling their credit card service center numbers (shown above or available on-line for other countries) to see if they can connect you directly to your bank.