The UK spent £2.32 billion on contactless cards in 2014 so we should probably understand the tech to stay safe.

The popularity of contactless cards has surged over the last year, with a record £2.32 billion spent using this payment method in the UK in 2014.

How do they work?

They can be used to pay for items by touching a reader at the till, rather than having to enter a pin number. The current contactless limit for a single transaction is £20 and it will increase to £30 from September 1.

The cards contain a chip that holds your account information and an antenna that picks up power from a signal sent out by the card reader.

Card companies will limit the number of contactless transactions that can be made in a row before you are asked to enter your pin though, and the limit could be about £50 or five transactions.

How popular are contactless cards?

Their popularity has increased rapidly in recent months as a widening array of places now accept them and consumers have found them an increasingly convenient way to pay.

There are now 58 million contactless cards in circulation. More contactless transactions took place during the first nine months of 2014 than the previous six years combined, according to trade body the UK Cards Association.

What can I do to protect my card?

There are metal cases which claim to protect cards, although Which? said it has not yet tested their effectiveness. But Which? said that in its tests, wrapping a card in tin foil prevented it from being read, even when it was rubbed against a reader. The consumer group believes therefore that while it is not essential, lining your wallet with foil can help to protect your card details.

To prevent the risk of accidentally paying with the wrong contactless card, it is also wise to take the card you want to use out of your wallet to touch it on the reader, rather than waving the wallet over the reader.

How likely is it that someone will copy my card details?

Which? said that although the risks are low, it is possible, although someone would probably have to be very close to you to “lift” your card details without you knowing. In the consumer group’s tests, the card had to be touched against a mobile reading device, although it said that other readers might be more powerful.

Figures from the UK Cards Association show that in 2014, the total annual contactless fraud loss was £153,000 compared with total spending of £2.32 billion. This represents 0.7p in every £100 spent on contactless. Total card fraud losses (all forms, not just contactless) stood at 7.5p in every £100 spent on all debit and credit cards in 2014.

Will I get my money back if someone does use my card details fraudulently?

Card providers should reimburse victims of contactless fraud, as long as they have acted reasonably to keep their card safe.