Controlled foreign corporation (CFC) rules are features of an income tax system designed to limit artificial deferral of tax by using offshore low taxed entities. The rules are needed only with respect to income of an entity that is not currently taxed to the owners of the entity. Generally, certain classes of taxpayers must include in their income currently certain amounts earned by foreign entities they or related persons control.

A set of rules generally defines the types of owners and entities affected, the types of income or investments subject to current inclusion, exceptions to inclusion, and means of preventing double inclusion of the same income. Countries with CFC rules include the United States (since 1962), the United Kingdom, Germany, Japan, Australia, New Zealand, Brazil, Russia (since 2015), Sweden, and many others. Rules in different countries may vary significantly.