Study shows as gas prices increased 80% between 2004 and 2011, card fees grew 180%.

A new study by the National Association of Convenience Stores (NACS) called “Hidden Bank Fees Siphon Money from Customers and Merchants at the Pump,” shows drivers are paying 6-10 cents a gallon in hidden bank fees every time they purchase gas.

What’s more, the banks’ “swipe” fee goes up inexorably with the price of gas, even though the bank is doing nothing extra to process the debit or credit card transaction.

Swipe fees continue to be c-store owners’ largest operating expense after labor, costing more than rent and more than utilities. Convenience stores paid more than $11 billion in card fees last year, a jump of almost 25% and an amount almost 90% greater than their profits.

“These fees have come to be a tremendous burden on convenience stories, most of which are run by small business people,” said Lyle Beckwith, senior vice president of government relations for the NACS. “In many cases, the banks are profiting more from the sale of gas than our members.”

As gas goes to $4 in some markets, the bank’s average cut of swipe fees alone increases to seven cents if customers pay with a debit card, and it can cost stores up to 10 cents if they pay with a credit card.

Customers paying with cash are still paying for the extra fees because the credit card companies’ rules push the merchant to pass along the costs to everyone, not just customers who pay with plastic.

The study also found that gas prices increased 80% between 2004 and 2011. Card fees rose 180%. In other words, even when gas prices level off, the bank fees continue to rise.

Because credit-card fees are fixed in secret by a duopoly of MasterCard and Visa, they always are on the increase, to the point where they are now the highest in the industrialized world.

For a copy of the report, “Hidden Bank Fees Siphon Money from Customers and Merchants at the Pump,” click here.