Shoppers making contactless card payments are being hit by new security rules that block transactions after they have made five tap-and-go payments in a row.

Customers trying to pay this way are complaining that their cards are being declined – despite having adequate funds in the bank and an up-to-date card.

But what many do not realise – and many shop staff are not aware of either – is that when a message saying ‘card declined’ flashes up, chip and PIN payments will be accepted instead.

From now on it will be more common for people to be asked to use chip and PIN. This is because of new industry-wide rules introduced this month designed to stamp out fraud, known as ‘strong customer authentication’.

Shoppers making contactless card payments are being hit by new security rules that block transactions after they have made five tap-and-go payments in a row

Banks, online shops and companies processing payments are required to better verify customers’ identities.

For contactless payments, the rules now state that every time a sixth consecutive contactless payment is attempted – or if the cumulative value of consecutive contactless transactions exceeds €150 (around £135) – the card must be authenticated.

This means the customer proving who they are by entering their PIN or using so-called biometrics, such as the fingerprint scanner on their phone to complete a payment.

But ‘card declined’ messages flashing up at the point of sale are wrongly leading people to believe there is a problem with their accounts.

Martyn James, of online consumer complaints service Resolver, witnessed people affected by this at a recent music festival. He says: ‘I watched people getting frustrated that their cards were being declined and some were panicking after spending an hour queuing for drinks.

‘All they needed to do was put the card in the machine and enter their PIN. Yet people working in retail don’t know about this major change either.’ He says it would be much simpler if all card machines simply instructed customers to ‘enter PIN’ rather than a negative message suggesting there is a problem. Industry experts say the technology is ready, but not all merchants have adopted it yet.

Mobile phone-based bank Monzo is warning customers it will tackle the problem by sending a notification via its app telling them to retry with a chip and PIN payment because ‘sometimes the card machine will just decline without a reason’.

NatWest has been trialling a contactless bank card that works in tandem with a fingerprint, cancelling the need for a PIN entry. Apple Pay and Google Pay users already prove their identities in shops with their phone and thumbprint.