• by Steve Smith  @popeyesm, September 19, 2011

While it lives only on one phone running on only one carrier, the mobile payment system using near-field communication (NFC), Google Wallet, is expected to launch today. The Washington Post reports that documentation sent to partners in the effort tagged Sept. 19 as the rollout day.  

Google Wallet is the search provider's major play into the mobile payment competition. Using its own Google branded Nexus S 4G phone running only on the Sprint network, Google Wallet employs NFC technology to make tap-to-pay payments at select retail vendors.

MasterCard is the only credit-card payment partner declared so far for the service, which requires in-store hardware. The WaPo reports that the documentation it has seen suggests that Citi MasterCard PayPass terminals will be the main provider used in the system.

Google will be tying mobile payments in with its own localized deals service, Google Offers, so that customers using the offer at the designated merchant will automatically receive the discount when paying. Google has named more than a dozen retial partners, including Subway, Foot Locker, Bloomingdale's, Macy's Walgreen's and Radio Shack.

Google Wallet payment partner MasterCard is also one of the members of a larger "ISIS" coalition of carriers, credit-card companies and technology providers that will likely be formidable competition for Google. PayPal also just announce last week it planned to introduce mobile payment solutions. Google rolled out a video recently promoting the Wallet, using Seinfeld character George Costanza as "Our First Google Wallet Customer." Using footage form the famous sit-com episode in which George's overstuffed wallet explodes on a New York City street. "Goodbye, wallet," the video promises. "The phone will take it from here."