Mezuzah in Rented Office

My husband rents an office. Does he need to put a Mezuza, if he does, does he need to put it in every room? Is the answer different if the office is not in Israel?

There are two basic opinions on this matter. There are those who exempt an office from a Mezuzah since it does not serve as a home (Rashi Sukah 8b) and those who oblige offices nowadays to place a Mezuzah (Aruch Hashulchan). In practice he should put it on without a Brachah in all the rooms he uses. This applies to Israel and outside.