An anonymous reader writes "Bloomberg reports that AT&T, Verizon, and T-Mobile USA will be dumping over $100 million into developing their mobile payment system, Isis, in an effort to battle back against Google Wallet. 'Isis aims to get ahead of its rivals by relying on its carrier partners' existing distribution network and customer relationships. Phones set up for Isis service are expected to be available at carrier stores in the trial cities. ... The carriers could potentially preinstall Isis software onto their phones, making it easier to use. They also may push handset manufacturers to adopt Isis software.'"