Hi, about ten years ago we had a break in London and used the trains/ underground to get around. We soon found out that we should have used oyster cards and because we didn't we paid more.
Is this still a thing please? If it is can someone explain it to me like i'm ten years old please? Can we not just use debit cards and if we can how does that work please with two teenagers who will be paid for by us? One of the teens doesn't have their own card and is disabled so we wouldn't be able to transfer money to him.
I'd really appreciate some help please, i've no idea about this. I'm from a "proper" Northern town.