Most organisations operate staff mess or canteen facility for its employees where payments for food items are made with money coupons rather than cash. In such coupon-based transaction system, the management needs to decide the denominations in which the coupons should be printed and also the proportion in which these denominations should be combined to form a coupon book which is made available to the employees. These decisions are made with the twin objectives of minimising the total number of coupons used as well as ensuring that most transactions are feasible. This paper reports the details of the method used for studying such a problem in a specific organisation. The study arrives at an optimal mix of coupons which leads to a significant improvement over the existing practice.