Was not going to comment on this topic, but just wanted to say that my legacy bank is the Clydesdale Bank and they issue Mastercard debit cards and have done so for several years. No questions asked at ATM it just works like a debit card. I initially had loads of issues when they first changed from maestro, retailers treating it as a credit card rather than a debit, taken a good few months for it to settle down. So would assume it’ll be same for Monzo.