The system is based on a TAP sticker that attaches to the back of mobile devices and is designed to provide secure data transfers. Inside the sticker is an EMV chip containing all the data required to complete payments as if the customer were using their card. The data transfer is fully encrypted and comes with complete security guarantees.

Customers will be able to make payments using their mobile device in the same way as they would using their contactless card and with the same transaction limits. If the transaction is over 20 euro the customer will be asked to enter their pin code into the terminal.

La Caixa has developed a free application to accompany the system launch, which will be available from the bank's applications store, CaixaMóvil Store, as well as other download sites, in versions for iOs, Android and Blackberry. The TAP application allows users to view transaction histories and account balances.

The bank will issues the first stickers to 5000 customers in December. In January sticker distribution will gradually be extended, reaching 200,000 users by February.

La Caixa currently has more than 1.12 million contactless cards in circulation which can be used for low-value payments at more than 50,000 retailers across Spain. It has worked with the Barcelona City Council, the Metropolitan Taxi Institute and Mercats de Barcelona to roll out the contactless system to taxis and municipal markets and has installed a network of 730 contactless ATMs that can be operated without requiring users to enter their cards.

The bank says more than one million contactless transactions have been completed since the nationwide launch in January 2012.