What will happen if I attempt a contactless payment over the advertised limit?

Question

I work at a food retailer and we accept contactless payments. I've noticed that our card machines still display the Contactless and Apple Pay symbols when a bill is above the limit for contactless payments.

Presumably this means that the card machine will still read a contactless card; what will happen if a bill is above the advertised limit for contactless payments (currently £30 in the U.K)?

I've asked and apparently nobody has ever attempted to pay with contactless above the limit in our branch, and as a result nobody seems to know what happens (management do not seem to know either).

Some things I can think of that could possibly happen:

• The advertised limit is a 'soft' limit- anything above will go through but is not protected by the bank's/payment provider's anti-fraud policies;
• The card machine immediately rejects the payment;
• The card machine refuses to read the card although the 'contactless' symbol is displayed;
• Payment is attempted, but the bank declines the transaction

What will actually happen?

Answer 1

For contactless cards, it seems that it will prompt to insert the chip card (so it can do a normal chip+pin verification) and/or enter the PIN, probably depending on the card issuer and/or the terminal software. See this FAQ for example.

For Android or Apple pay, it depends on the POS software. If the software supports it, it may simply allow it even at a higher limit; Apple pay allows any amount with authentication (for all transactions), while Android pay has a limit of £100, and will require a device authentication (fingerprint or device PIN) over £30. But some software may still enforce a lower limit (£30 or even £20 if it's really old).