Any card transactions over £100 needs you to enter your PIN.
Once 150 euros (GBP equivalent) has been spent accumulatively on the card with no PIN transaction in between, you'll be prompted to enter your PIN.
This has been introduced as part of the Strong Customer Authentication regulation to make card payments more secure.
Why isn't my contactless working?
Learn why your tap to pay isn't working and when you need to enter your PIN. Understand spending limits and security rules for touch-free card payments.