In a commercial transaction system, a system user uses a personal computer to interact with merchant computers over the Internet to conduct cashless transactions. Each system user computer processes data including a balance stored in the computer's memory and updates the stored data at the end of the transaction. The system is specially designed for purchases of items or transactions of relatively small monetary value. In this manner, the amount of the transaction is deducted from the balance on the computer. In accordance with the invention, when the existing balance associated with the computer does not cover the price of the transaction, the system provides a reload feature which gives the user an option to increase the balance of the computer. Such a feature allows the purchase to be made without inconveniencing the user to increase the balance by other means. Each time the balance is increased by a reload, the user's issuer bank bills the user for the reload amount.