Isis, the contactless mobile payments venture set up by major US network operators has brought on board Visa, MasterCard, American Express and Discover.
AT&T, T-Mobile and Verizon Wireless set up Isis last year, banding together in a bid to gain a slice of the rapidly expanding and competitive mobile payments market.
The venture plans to roll out its service in Salt Lake City, Utah and Austin, Texas in the first half of next year before gradually spreading the offering nationwide.
The agreement with card firms means Americans with Isis-enabled phones will have ubiquity and freedom of choice when it comes to payment network acceptance.
The move to bring on board all four major card networks is the result of a change of approach made earlier this year when an exclusive agreement with Discover was ditched and the system opened up "to all merchants, banks, payment networks and mobile carriers".
Michael Abbott, CEO, Isis, says: "By working with the nation's payment networks - Visa, MasterCard, Discover and American Express - we significantly advance the vision of an open and secure platform that provides banks and merchants with a new and highly relevant way to connect with consumers."
Joe Saunders, CEO, Visa, adds: "Visa has long championed an open approach to mobile commerce that allows consumers to choose which account they want to enable for mobile payments. We are committed to working closely with Isis, handset manufacturers, platform providers and financial institutions to offer consumers a suite of mobile services - mobile payments, coupons tailored to location and lifestyle, real time account information and more."
Despite its inclusive approach, Isis faces considerable competition. Sprint, the other big US mobile network operator, has spurned its rivals and is working on a rival service it hopes to launch by the end of the year. The biggest challenge though is likely to come from Google, which is piloting its wallet, using the MasterCard network, this summer.