1. A method performed in a programmed computer system for administering an on-line payment system, the computer system maintaining a database containing account information for a plurality of user accounts, the method comprising: a) receiving deferred remittance information indicating an amount to be deposited by deferred remittance to a bank account associated with the computer system, for application to a first one of the user accounts; b) adding the amount to be deposited to a balance in the first one of the user accounts and marking the added amount as being uncleared in the database; c) receiving a deposit notification indicating an amount of a remittance which has been deposited in the bank account for application to the first one of the user accounts; and, d) reconciling the deposit notification with the deferred remittance information by: i) if the amount of the remittance is equal to the amount to be deposited, marking the added uncleared amount as being cleared in the database; ii) if the amount of the remittance is less than the amount to be deposited, marking funds in the added uncleared amount totalling the amount of the remittance as being cleared in the database; and, iii) if the amount of the remittance is greater than the amount to be deposited, marking the added uncleared amount as being cleared in the database and adding to the balance in the one user account an amount equal to the excess of the amount of the remittance over the added uncleared amount.