@viccie30
On second thought, my parents may not have signed anything either. I do remember my brother was gifted an account with 100 DKK (~12 EUR) back in the day by a different bank (yes, that was a thing back then, no signatures, id or anything), and they let the account go negative. In the end, the bank had to swallow that debt, because they didn't have any legal basis for demanding that he pay.