Q: I was entrusted with a sum of money. May I use it temporarily and return other money?

A: We learned that a guardian may not misappropriate an entrusted item for his own use (C.M. 292:1). However, since it is expected that money is spent and replaced, sometimes the guardian is allowed to use it. For example, a banker or moneychanger who was entrusted with money is permitted to use it unless there is a contraindication (e.g. the money was entrusted in a sealed envelope). On account of this privilege, even an unpaid guardian has the heightened status of a shomer sachar; if he uses the money, he becomes a sho’el (292:7).

Some authorities write that since money is continuously needed by everybody nowadays, the rule of a banker pertains to all (Sm”a 292:18; however, see Pischei Choshen, Pikadon 5:53).

If the person was entrusted to deliver money or to buy something with it, many authorities do not allow him to use it meanwhile, since the money was not entrusted for any length of time (Pischei Teshuvah 292:2). If he does, some consider him sholei’ach yad (embezzling). Even when the guardian may not use the money, many authorities permit him to do so if he designates other money immediately in its place (Pischei Choshen, Pikadon 5:20-21).