"While Visa cannot lower the price of crude oil, there are things we can do to help make the process of buying gas easier for our cardholders. And by lowering our rates, we hope to see oil companies pass these savings along to their stations and ultimately to consumers," said Bill Sheedy, global head of corporate strategy Visa Inc. "As oil prices rapidly rise to unprecedented levels, we are accelerating our ongoing efforts to address the issues in the fuel segment."

The card brand made the change after gasoline retailers began to complain they could no longer afford to accept cards. At an interest rate of 2%, the interchange payments rose with the price of gasoline and retailers said it was completely swallowing their narrow margins on a price per gallon basis.

Further problems with some cardholders and card issuers were beginning to arise as well. Due to transaction processing methods, cardholders were facing large holds on gasoline purchases and card issuers complicated authorization decisions.

Visa said, for example, a motorist using a Visa Signature credit card, which carries the highest interchange, to fill a 15-gallon tank at $4 a gallon–or $60 total–would cost the acquiring institution $0.94 in interchange fees, a savings of 14% over current rates.

Using a debit card, that same transaction could be cleared within hours, quickly removing the $60 hold that is often placed on a consumer's funds for one or two days in the current system.

For higher transaction amounts, the interchange grows, up to 59% on fuel transactions, the card brand explained.

"People are frustrated enough with the price of gas today; they shouldn't be frustrated with the payment process as well," said Sheedy. "We took an entirely new approach to processing fuel payments, and created a solution that removes many of the major barriers that consumers and station owners face today at the pump."

The technical changes will both reduce hold times and provide the income to the retailer immediately.

Merchants were skeptical of the cap. "While we welcome any recognition by Visa of the interchange fee pain, the confusion and potential negative effects of these changes might have been avoided if this were the result of a negotiation between merchants and Visa," said the Merchant Payments Coalition, a group of merchant trade associations that coalesced around the interchange issue.

"H.R. 5546 and S. 3086, the Credit Card Fair Fee Act, would allow that to happen and ensure a market process for interchange fees with benefits to consumers throughout the country," the coalition said.

The merchants, in particular, questioned why the cap on debit card interchange was put into place quickly and not the changes on credit interchange.

"While the devil is always in the details, and we haven't seen any details yet, it looks like the new structure for credit cards combines a higher fixed fee with a lower percentage fee," said Hank Armour, CEO of the National Association of Convenience Stores. "The net result of this combination may actually be higher fees for those transactions under $60 for those customers using regular Visa credit cards without a rewards program."

On debit card transactions, the cap on interchange may only apply to gasoline purchases of more than $97.50. That is a small number of transactions–especially because Visa banks reserve the right not to give gasoline retailers anything more than $75 on a sale, Armour complained.

"Unfortunately, we may not know the impact for months because Visa has said this will only affect debit card transactions on gasoline in mid-July and won't affect credit card transactions until October–long after the end of the summer driving season [and the opportunity for congressional action]," he added.

No analysts would speak on the record about the impact the interchange cut could have on the card brands' ongoing legislative fight over card interchange.

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