As we draw ever closer to the annual bacchanal of beer, buffalo wings, and sports betting that is the NFL playoff season, Washington’s top consumer watchdog has a word of advice to fans: Don’t place your wagers using a credit card.

Why? Because it’s expensive. Credit card companies that allow sports gambling transactions typically treat them as cash advances, the Consumer Financial Protection Bureau noted in a new report first shared with Yahoo Finance. That means they come with additional fees — frequently $10 per swipe or up to 5% of the total charge, whichever is higher.

Those extra costs can end up eating into your winnings, especially on the kinds of small bets that surge during the Super Bowl. Worse, those fees may be catching many fans unaware since they’re often only mentioned deep inside credit card agreements under examples of what might constitute a cash advance.

“If you’re at a sports bar and want to make a bet, are you going to look at your credit card agreement to check page three, paragraph five? I think there may be some disconnect there,” a CFPB official told Yahoo.

While data on the topic is limited, the agency does turn up some evidence that bettors may be getting ambushed. Credit card advance fees jumped far above the national average in both Kansas and Ohio after sports gambling was legalized in those states, before eventually somewhat settling.

The pattern suggests that many Chiefs and Bengals fans experienced price shock after betting with their Visa for the first time, then switched to a cheaper method, like a debit card. Still, cash advance fees remain elevated in those states compared to before sports gambling was legalized, suggesting many fans are still relying on credit.

A handful of states — including Massachusetts, Rhode Island, Iowa, and Tennessee — ban residents from using a credit card to place sports bets. Advocates have suggested it could help prevent fans from getting in over their heads in gambling debt at a time when gambling increasingly appears to be taking a financial toll on American households.

“If you want you lose your paycheck, that’s fine,” Iowa Senator Tony Bisignano of Des Moines told a local radio station in 2020 after the state made the move. “I don’t know how long you get away with that from your family, but with a credit card, you can run a debt that can’t possibly be paid.”

Jordan Weissmann is a senior reporter at Yahoo Finance.

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