You may not be able to keep hackers or dishonest employees out of your credit card processors' office, but you can keep thieves from filching your credit card information from the garbage.

Consumer advocates and credit card companies say people can take simple defensive measures, from checking statements often online to calling their credit card company immediately if a monthly statement doesn't appear in the mail.

Credit card fraud is in the spotlight after a string of data thefts and losses, most recently the disclosure that 40 million credit and debit card accounts were at risk for fraud after hackers broke into a company that processes payments for all the major cards in the United States.

Still, credit card fraud is on the decline in the US.

Issuers lost only 4.7 cents for every $100 in credit card charges in 2004, down from a peak of 15 cents for every $100 in 1992, according to The Nilson Report, a trade publication.

Why is fraud down? Cheap telecommunications costs mean that 98 per cent of all transactions receive authorisation. Systems built by Visa and MasterCard also run transactions through fraud-monitoring neural networks before they're authorised, according to Nilson Report.

Visa introduced an authorisation system last week that checks each transaction against system-wide fraud patterns and personal spending habits.

Such security measures mean that some unusual transactions can be denied.

When New York swimsuit designer Judy Knight went on a buying trip to Cancun recently, American Express froze her card while she was shopping.

The company wouldn't let her make purchases even after she got on the phone at one shop and verified her account number, her mother's maiden name and her own social security number.

Knight was able to use the card only after an American Express representative checked her voice against her voicemail at work and spoke to her office receptionist to confirm she truly was an employee.

"She came back on the phone and said, 'Yeah, that's you,'" said Knight.

Yet even as the rate of credit card fraud shrinks, it remains a threat that consumers can fight by taking commonsense precautions:

• Make sure your credit card company has your current phone number so the company can call you if they see a suspicious pattern of charges on your card, said Tom Kelly, a senior investigator at Stroz Friedberg Investigations, a division of a computer forensics and technical services company.
• Don't use a debit card over the Internet. Your credit card fraud liability is limited at $50 but debit card fraud could drain your checking account, said Ed Mierzwinski, a consumer advocate at US Public Interest Research Group.
• If you get a phone call or an e-mail about suspicious activity on your account, give no information over the phone or online. Instead, take down the card representative's name and call them back at the number listed on the back of your card, Mierzwinski said.
• Keep track of your transactions. You should be able to tell a company representative what your last five transactions were, said Susanna Montezemolo, a policy analyst at Consumers Union.
• Use your credit card less, said Paul Richard, executive director of the Institute of Consumer Financial Education. His group sells credit card sleeves that read, "If you can eat it, drink it or wear it, it's not an emergency."
• Notify your card company if a monthly statement or an expected new credit card fails to arrive in the mail. Shred statements once you've checked to make sure they're correct. Shred credit card solicitations, too, so someone else doesn't apply using your name.
• Keep your receipts and check your credit card statement against them. If you have online access to statements, check them weekly, Montezemolo said. "Some people find, through an honest mistake, that a store has added an extra zero to a transaction," she said.
• Also be on the lookout for small unusual transactions, Mierzwinski said. "Sometimes the bad guys will test an account at a gas station," he said.
• Keep a record of your account numbers, their expiration dates and the card company's phone number in a secure place.
• Don't leave your credit card payments in your home mailbox. Instead, mail them at a post office or a secure mailbox.
• When you travel, be careful about using your credit card at Internet cafes or anywhere with a wireless connection.
• Check your credit report at least once a year.
• If you find incorrect transactions on your statement, call your credit card company immediately then write the company with the same information and keep a copy of the letter, Montezemolo suggests.

Taking precautions may seem like a pain, but the stakes are high.

"It's your financial well-being," said Montezemolo. "It's surprising how many people don't do the things we assume everyone does: Check their credit card statements and bank balances and balance their checkbook."

Brian Bergstein contributed to this report.