While traveling in Costa Rica a few years ago, I stopped for gas along a dirt road miles from anything resembling a major town. I gave the attendant my Visa card and waited in the car. A few minutes later, he motioned for me to come inside.

My credit card had been rejected, he said, using hand gestures to explain that there was a problem. I was stumped since I had just used the card a few days earlier to pay for a hotel room.

I could have called my credit-card company, but the gas station had no phone that I could use. It was late on a Saturday afternoon. Rather than hassle in 90-degree heat at a pay phone, I paid cash for the gas and used another credit card for the rest of the trip.

Only after I returned home and found a message from my credit-card company on my answering machine, did I find out what happened.

Even through I travel frequently, I had never used my credit card in Costa Rica. The bank's computers detected what's called an "abnormal-use pattern,'' and put a hold on my account.

The bank had phoned me at home to check on the charges. The problem was that I was in Costa Rica when they called. Unable to verify that it was me using the card, the bank put a hold on my account until they heard from me.

I learned some important lessons on that trip. Now before I travel, I call my credit-card company, my credit union and the bank that issues my ATM card and ask that they note where and approximately when (i.e. during the month of October as opposed to specific dates) I will be traveling.

I don't like the idea of telling someone when I will be away. But it's a trade-off I'm willing to make in exchange for being able to use my credit card or ATM card without being mistaken for a thief.

Even this isn't a foolproof guarantee there won't be problems; that's why I carry a second credit card with me, and I make sure I have the phone numbers I might need in case I have problems and need to call from another country.

All major credit-card companies have special toll-free numbers that can be called from overseas, and it's important to get them before you leave since the regular 800 numbers won't work outside the United States.

Credit-card fraud is a multimillion-dollar-a-year business. Banks say that we all pay for it in terms of higher finance charges and fees, but since most consumers are not held liable when their cards are used fraudulently, it's the financial institutions and merchants who take the direct hits.

Online retailers especially have been forced to eat huge losses due to credit-card theft, one of the biggest reasons that anti-fraud computer software has become more sophisticated.

Fraud-detection systems are built on lots of information. Taken into account are the dollar amount, time of day, day of week, types of merchants and geography.

Sometimes large purchases raise a red flag, such as if you normally use your card to go grocery shopping once a week, and suddenly use it to buy an expensive piece of jewelry in a foreign country.

The pattern of transactions from worldwide fraud trends are taken into consideration. This might explain why four friends I know who traveled together in Europe last year had their credit cards rejected in Italy, but not in Germany. My card was rejected in Costa Rica, but not in France.

The probability of having a hold placed on your card is high in Mexico and some Eastern European countries where there's a problem with "skimming,'' a system of producing counterfeit cards by making a copy of a real one after it's been handed to a waiter or hotel clerk.

This happens without you knowing it, and while your card remains in your possession. It's one reason why banks can't guarantee that they won't place a hold on your account if they start to notice unusual charges — even if you have notified them that you'll be traveling.

This is understandable, but it seems that credit-card issuers could be doing more to explain all of this to their customers. Their Web sites are filled with information about how to avoid fraud, but they're silent on the issue of computerized risk alerts and what cardholders can do to avoid problems when traveling. As it stands, most people find out what to do after the fact.

Remember, if your credit card is lost or stolen, under federal law, you're liable for nothing if you report the loss before the card is used. In any case, the most you will owe is $50 per card, assuming you make a report.

And you're free from liability if unauthorized purchases are made when you are still in possession of the card (such as charges made with a stolen copy).

Visa and MasterCard debit cards can pose greater risks. If stolen or copied, they can be used for purchases, with the payment deducted directly from your checking account.

Under federal law, the amount for which you can be held liable depends on how quickly you report the loss.

Although most card issuers offer better protection than what the government requires, trying to recover money once it's gone is a hassle you don't need. Check with your financial institution on its policies.

As always, it pays to do your homework before you leave. Call your credit-card company and get the toll-free numbers to call from the countries you will be visiting. The numbers are also posted on the Web at www.visa.com and www.mastercard.com. See www.ftc.gov for details on your rights under the Fair Credit Billing Act for credit-card charges and Electronic Fund Transfer Act for ATM and debit-card transactions.

(I copied this informative article with good advice from the May 28, 2002 edition of the Seattle Times.)

Good info. My Visa was cloned once (Travelodge in San Ysidro) and over $1000 in purchases were made of women's clothes in Hermosillo Mexico within several days. Since then this particular bank has called me on several occasions to verify unusual purchases that I have made (but they never called when I bought my membership to this site). I like this a lot and always tell them so. Ditto with clerks that check my driver's license when I use the credit card.

www.visa.com says you can call this number collect anywhere in the world: (612) 9251-3704 seems like too many numbers, doesn't it?

Also, for Thailand, they give: 001-800-441-3485

Here is the number given to me for my visa card, 410 581 9994.
Anyone has the number for American Express?

Here is the AMEX number:
collect International 1-336-393-1111