A tax or levy system, or a document which outlines the conditions under which taxes and levies can be charged. Tariffs are normally filed with governments or regulatory bodies and approved by these same bodies. Tariffs typically list schedules for rates, contracts, and contract and rate eligibility. When provided in printed or digital document form, tariff documents may include terms and conditions, sample forms, copies related legislation or regulations and other related information. Tariffs are used in virtually all service industries.

Tariff is widely misinterpreted as referring to a tax or other form of levied charge. A tariff merely sets out the conditions for those charges; it does not represent the charge itself. Thus a tariff rate is a charged rate as it is outlined in a tariff schedule.