NFC based payments system ISIS is coming to Windows Phone, as the carrier supported network is set to roll out across America later this year.

Anyone with half an eye on the payment industry, especially in the US, will note that Google's push on Google Wallet has not convinced the carriers to go with the Mountain View system, but to push forward with their own joint venture (the aforementioned ISIS) through a number of city-wide trials, including Salt Lake City and Austin.

The national roll-out during the rest of this year will take ISIS into many mainstream retailers, and will undoubtedly be backed by a significant PR push from the networks.

The trial was focused on a limited range of Android devices, but the geographic expansion will take place at the same time as a device expansion, with iOS, BlackBerry, and Windows Phone handsets joining the ISIS system.

Naturally Windows Phone is well placed to support ISIS, with many handsets sporting NFC, and Microsoft's Wallet application a default application across every handset... and I'm intrigued how the NFC payment system will work on the NFC iPhone handsets...

ISIS' mobile wallet has received attention because it is backed by AT&T, Verizon, and T-Mobile. Given the strength of operators in the US that gives a greater chance of success (or at least access to handsets) than competing solutions.

The ISIS implementation will vary from platform to platform and from device to device, but in most cases there will be an ISIS specific wallet app. Existing cards can be added to this app (currently supports American Express, Chase Freedom Credit Card and Capiatl One Credit Card), which can then be used to make contactless payments (similar to a PayPass of PayWave equipped credit card). In addition the ISIS wallet will support loyalty cards and vouchers.

As with other mobile payment solutions the main stumbling blocks are likely to be the user experience (not as easy as simply using your existing card) and whether you existing card is supported (can be put in the digital wallet).

There are more details at the ISIS newsroom.