With 233 million U.S. subscribers, including banks and financial institutions, mobile access has achieved an amazing 78 percent penetration rate, now making mobile more extensive than the Internet. Now banks and financial institutions are starting to work with carriers to tap their customers via this nearly universal medium. The four keys to adopting mobile finance, according to Bango Inc.'s Anil Malhotra, are multiple billing methods, usability, security, and carrier business models. Mobile banking has officially arrived now that AT&T Inc. and Verizon Wireless have both gone live with mobile banking campaigns with financial institutions such as SunTrust and Wachovia. The banks use a platform from Firethorn Inc. to allow customers to download secure applications to check their balances, and customers can pay their AT&T bills via their mobile devices. Jim Straight, VP of consumer products for Verizon Wireless, believes basic account access will eventually lead users to more advanced applications such as m-wallet tactics and peer-to-peer payments. Some financial providers are taking a completely skeptical view of mobile carriers. Going beyond the current basic m-banking services now being introduced in the U.S. will need an array of billing validation systems, integration, credit checks, and business modeling. Some transaction models remain problematic, and the idea of allowing mobile purchases of hard goods raises many issues that must be answered before that idea can be implemented. It is not certain how m-finance will continue to develop, only that it will continue to develop.