This note outlines the ways in which performance of contractual obligations may be transferred to a third party by means of a subcontract. This note provides an overview of the concept and the use of subcontracts. It covers the position where the main contract is silent on whether subcontracting is permitted, restrictions on subcontracting, whether the subcontract must be in writing and the liability of a subcontractor to a principal. It also covers common terms that are found in back-to-back subcontracts which are used to pass through, or flow down, obligations to a subcontractor.