Ryan does this too ( he is in yr7) they also have a no money in school policy too.
Parents send in a cheque or log onto the school website and put in money into their kids account, then when the child wants to buy something e.g lunch or snacks they have a finger print check out system that debits money from the account.
When we put money in we can restrict how much is spent per day and we can even view what he is buying
If the child needs money for the bus they can go to the office and get money out of their account.
I think its a fantastic idea