While EE was announcing that it has signed a deal for contactless payments in the UK with Mastercard, Pocket-lint was in Bratislava, the capital of Slovakia, learning how Visa and O2's system works in what the finance company calls, its hero state. As part of that, we were treated to a dummy sign-up session with Tatra Banka,\u00a0the bank the companies have paired with, which showed us how they get around the fact that the iPhone doesn't come with NFC in-built.The iCarte is nothing new, having been announced by Visa Europe at the beginning of 2011, but the iCarte 5 (aka iCarte 520) literally only came into the Slovakian bank the day we visited. It is designed specifically for the iPhone 5, with a Lightning connector and elongated form factor, but is essentially the same piece of kit as the original.Effectively, it adds NFC capability to the iPhone. Almost every manufacturer bar Apple has adopted the technology in their flagship phones for a while: the Samsung Galaxy SIII, S4, HTC One, Nokia Lumia 925, BlackBerry's Z10 and Q10, and many many others feature NFC antennas and capability. The iPhone doesn't, not even the iPhone 5.Therefore the iCarte 5 is one of the only ways iPhone owners can take part in the contactless payment revolution and, to be honest, it's not a bad way of doing so.They are issued by banks and locked to Visa because of a business partnership between Visa Europe and Canadian manufacturer Wireless Dynamics. Royal Bank of Scotland and Nat West banks in the UK carry the previous version for iPhones 4 and 4S, and presumably this latest one will become available too. However, our experience was based on how Tatra Banka issues the device to its customers.A customer visits the bank, asks for an iCarte and the process is remarkably simple. The bank employee gets one of the devices from storage, assigns its unique code to the customer's account and that's it. Having placed the iCarte on their device, all that's required is the download of an app, activation and it's up and running.Within minutes the customer can use the iCarte to pay for purchases in any retailer who accept contactless payments. Like with a SIM-based solution for NFC-capable handsets, the customer can spend up to 20 euros before having to enter a PIN code, and the application tracks spending. Where it differs from an NFC SIM or Android phone is that the app has to be running to pay, whereas the SIM version doesn't even require a phone to be on to work. In comparison, the iCarte 5 solution doesn't need any input from a network, so will work on any carrier.Tatra Banka charges a 50 euro fee for an iCarte or iCarte 5, partly to pay for the device itself, partly for activation. However, until the end of the year, to encourage adoption, it has halved the price to 25 euros. You might find similar incentives in your region.In the hand, the iCarte 5 when attached to an iPhone 5 is actually very light - not dramatically heavier than a conventional iPhone case. And it protects the phone in a similar way too. There is a lump that sticks out from the bottom, which adds length to an already lanky handset, so may not appeal to all, but convenience outweighs any concerns over aesthetics.Surely that's the point.