Up to what amount can the customer pay without entering a PIN code?

UK

For transactions up to 100 GBP, the customer is not required to enter a PIN code. However, PIN code entry may be required for lower amounts due to card security and is specified by every merchant.

Slovenia & Romania

For transactions up to 25 EUR, the customer is not required to enter a PIN code. However, PIN code entry may be required for lower amounts due to card security.