Set of contracts
The contractus trinus, contractus triplex, or simply triple contract, is a set of contracts used by European bankers and merchants in the Middle Ages, notably by the Fugger family, as a method of circumventing the canon law prohibition of usury.
Some Muslims are of the view that the present practice of Islamic banking relies on devices similar to the contractum trinius as a means of working around a ban of riba (usury) in religious scripture.