Citibank Singapore recently rolled out a new way for credit card holders to make payments: using their fingerprints. "It’s an investment for our future," says Anand Cavale, vice president and business director of credit payment products at Citibank Singapore, noting that this is the first time Citibank has used a biometric payment system anywhere in the world. Customers use the system by pressing a finger to a sensor at the cash register in outlets like coffee shops; the purchase amount registers to the corresponding Citibank account.

With an affluent, tech-knowledgeable population of 4.5 million, Singapore is a competitive market for credit card issuers. Banks must look for any edge they can find. To encourage spending, banks regularly team with partners to offer special discounts—say, 10 percent off dinner at a trendy restaurant—if customers use a certain credit card.

Citibank hopes the biometric technology makes purchases more convenient when time matters: "If you’re running to catch a train and buying a cup of coffee and a newspaper, your time has more value," Cavale says.

So far, the biometric payment systems are in place at only a few outlets in Singapore, including local retailers, clubs, restaurants and cinemas, and work only for holders of Citibank Clear Platinum cards. But the bank has plans to quickly expand the number of such systems and the number of Citibank cardholders able to use them. Citibank began with the Clear Platinum card because it is targeted at younger customers, ages 25 to 34.