>>> I was told by my bank that, for security reasons, chip and pin is needed after every five contactless payments
I keep seeing posts like that one (with the number of transactions quoted often being six, rather than five). However 'in normal times' I probably use my contactless card at least three times every day (and often more), with it only 'locking up' roughly once a month. So that's possibly around a hundred transactions before it 'locks', not five or six!