Despite their heavy credit card use, Sen. John McCain and his wife Cindy likely did not pay much in interest in 2007, nor have they likely carried unmanageable card balances into 2008, sources say. McCain's press office did not return CardLine calls requesting comment on whether the McCains revolved any of their card balances listed on his 2007 annual disclosure to the Senate of family assets and liabilities. An AmEx spokesperson says its charge cards usually charge late fees instead of interest on balances not paid by billing dates. But, she adds, AmEx allows some cardholders to enroll in a free payment flexibility benefit, which enables them to revolve certain high-value transactions or balances for short periods, such as a month or two. "We look at different risk profiles and your relationship with us," the spokesperson says. "Say you just had a very expensive vacation. It's an added flexibility for certain charges." Ken Paterson, director of the credit card advisory service of Mercator Advisory Group, tells CardLine it would not be unusual for a wealthy cardholder such as Cindy McCain, who is heir to a beer-distributorship fortune reportedly worth $100 million, to have a high balance on a super-premium charge card and to pay the balance before incurring interest or late fees. "Super-premium cards are designed to accommodate large monthly spend for individuals who do a lot of transacting and who have the ability to pay," Paterson says.