The Plastic Card Security Best Practices are based on research of claim files to determine why losses occurred, as well as on-site assessments at hundreds of credit unions, according to Ryan.

The recommendations include a mix of "common-sense" measures and some that could result in increased costs for credit unions, he said.

They include the need for round-the-clock monitoring of transactions for potentially fraudulent activity. Such monitoring should go beyond fraud models that simply score transactions for risk. CUNA Mutual wants credit unions to be able act on fraud alerts immediately and have measures for checking the card validation codes for all personal identification number debit transactions, as well as for Internet, mail, telephone and key-entered transactions.

CUNA Mutual's best practices also call for daily limits on card transactions to limit losses from fraudulent use of credit and debit cards. Similarly, credit unions need to set up their card authorization systems to automatically decline cards on which the name transmitted on the magnetic strip doesn't match the cardholder's name in the credit union's master file.

Corinne Sherman, vice president of card services at the Pennsylvania Credit Union Association, welcomed CUNA Mutual's initiative and said it would go a long way toward reducing fraud losses in the industry.