Portable electronic device

A portable electronic device comprising an integrated circuit card (10), which incorporates a data memory (32) and CPU (30) and is externally provided with a keyboard (18) and a liquid crystal display (16). The data memory (32) stores a variety of data which respectively indicates the maximum amount allowed for executing transactions during an effective term, the effective term for transactions, the maximum amount for transactions that can be renewed each effective term, and the effective term between renewals. In addition, the IC card (10) also incorporates a clock circuit (36) which generates data indicating the current date. When the card holder initiates a transaction using the IC card (10), the CPU (30) compares the data related to the current date with the effective term for transactions. If the CPU (30) identifies from the result of comparison that the present date is outside the effective term for transactions, the CPU (30) then automatically renews the effective term for transactions and updates maximum amount allowed for transactions by applying data indicating the effective term applicable to renewal and the maximum amount for transactions to be renewed.