Tax rules for personal use of business aircraft apply not only to aircraft owners, but to anyone making use of an aircraft, such as a lessee or even somebody just purchasing a charter flight. It is common that a plane may be owned by one company and leased to one or more affiliated companies. In that case each company must make its own calculations as to the consequences of personal use. Each has a distinct bucket of flights that are their flights and a distinct set of expenses. This often means that a single aircraft in a single tax year requires multiple sets of calculations to determine the tax consequences to each party involved.