Generally a list of charges, established by an organization for services or goods. For instance, a hotel tariff is the list of charges for various rooms, meals, accommodation over a period, etc. The word also has specialized meanings: (1) The Customs authorities issue a tariff showing dutiable goods together with the amount of duty payable. (2) There are what are known as two-part tariffs, where a set basic charge is made together with an additional charge which varies with the contract. For instance, a subscriber pays a set rental for a telephone, plus an additional charge which varies with the number of calls. (3) The term is also applied where one rate is charged up to a certain maximum and a higher or lower rate for purchases or orders above this level.
Reference: The Penguin Business Dictionary, 3rd edt.