Whilst RIM, LG and Samsung have already jumped on board the NFC bandwagon, introducing the wireless technology into their latest smartphones, we can expect the number of Visa-certified devices to at least double this year, Visa executive Andrea Fiorentino confirmed today at Mobile World Congress in Barcelona.

In 2011, the financial giant announced that it had approved six smartphones from Samsung, LG and RIM to utilise its new Visa payWave technology, helping to step up adoption of NFC payments and services on mobile devices.

The company certified Samsung’s Galaxy S II, LG’s Optimus NET NFC, BlackBerry Bold 9900, BlackBerry Bold 9790, BlackBerry Curve 9360 and BlackBerry Curve 9380, passing them through their vigourous testing procedures, which can take “between two and six months”, according to Fiorentino.

Vendors are submitting their NFC smartphones to Visa to be tested and approved months before launch, ensuring that they can be ready to submit and process NFC payments when they hit the market.

Fiorentino noted that once a vendor has a device approved by Visa, if the design and materials used on the handset stays true to other devices in a company’s smartphone portfolio, they have a “very high chance” that their new devices will be approved thereafter.

With Samsung already gaining approval for the Galaxy S II, it is highly likely that if future devices (its next flagship, for example) mimic its slim rectangular design and use of polycarbonate materials, it could be certified quickly.

Visa is effectively approving the NFC controller that mobile vendors are using in the device, ensuring that when coupled with an operator SIM card, a customer’s details are securely authenticated using the secure element on the device, without danger of being compromised. It also certifies that NFC applications can provide the level of security and user experience that is expected from a financial app of its kind.

When the devices are certified, it is then up to a bank or financial institution to offer an application for the smartphone. Visa merely ensures that Lloyds, for example, is able to guarantee an authentic and secure NFC payment experience, the actual transaction, app development and processing is down to the bank itself.

The same can be said for Vodafone, which recently announced it had partnered with Visa, although the carrier is expected to open up its service to a number of banks.