I don't think you get what I mean. Customer buys from store A and pays them the deposit and returns them to store B who gives the customer the deposit amount. Store A doesn't care, they got the deposit, didn't have to return it to the customer. Store B had to give the deposit amount to customer even though they didn't get the original deposit amount. See how it might be a nuisance to store B? That's why you need some organization for the system.