Abstract
Chargeback policies and practices are an important factor in the success or failure of computer-based information systems and services and are, therefore, a useful implementation tactic. Unfortunately, office communication systems like electronic mail and voice messaging do not fit the assumptions on which chargeback schemes are usually based. Implementors of office communication systems can avoid potential implementation problems related to chargeback schemes by avoiding usage-sensitive charging, by modifying charges for substitute products, and by altering users' awareness of charges.