IMAGINE a technology that lets you pay for products just by waving your cellphone over a reader.

The technology exists, and, in fact, people in Japan have been using it for the last five years to pay for everything from train tickets to groceries to candy in vending machines. And in small-scale trials around the world, including in Atlanta, New York and the San Francisco Bay Area, nearly everyone has liked using this form of payment.

But consumers in the United States won’t be able to wave and pay with their cellphones anytime soon: The myriad companies that must work together to give the technology to the masses have yet to agree on how to split the resulting revenue.

“In Japan it was easier,” explains Gerhard Romen, director for corporate business development at Nokia. “It was just the major guys saying, ‘This is how it will be.’ ” A single carrier, NTT DoCoMo, accounted for more than half the Japanese market at the time the system was rolled out and thus had significant leverage with financial institutions and handset manufacturers.

This is not the case in the United States. For such payments to work here, cellphone manufacturers, carriers, financial institutions and retailers must all play roles. There also must be some sort of intermediary that is trusted by both the financial institutions and the carriers to activate the virtual credit cards inside the phone.