Barclays has found a way to bring mobile payments to people whose phones aren't new or advanced enough to have a Near Field Communication chip built-in.
An NFC chip allows wireless communication over a range of just a couple of centimetres, meaning it can be used for "swipe" or "wave to pay" tools while drastically reducing the risk of data being intercepted. While some phones can already be linked to a card account and used for cardless payments in this way, the technology is only available in the latest models of most phones.
The Barclays solution is to create a small physical card called PayTag that contains an NFC chip, somewhat along the lines of the Oyster card used for payments in London. The card is designed to be stuck to the back of a phone, which can then be used with contactless payment terminals.
At the moment a PayTag card can be used for payments of up to £15, though this will rise to £20 in June. Although it's linked to a credit card account, the card works on a pre-paid basis, meaning it has to be "topped up" before spending.