Abstract: A conventional cash register unit is modified to include a cashier input unit having a switch and/or keys or the like for entering a limit value equal to the maximum total bill authorized for a given transaction by an individual customer. A limit indicator unit is coupled to the cashier unit for generating a signal to the clerk and the customer when the accumulated total, including tax, is within a predetermined margin of the limit value. Preferably, the limit indicating unit displays several kinds of information, including the authorized limit value, the running total of the accumulated bill, an alarm signal indicating that the accumulating amount is within a predetermined margin of the authorized limit, as well as a limit signal indicating when the authorized limit has been reached. Also, the price of each item may be displayed.