Also referred to as an engineering, procurement, construction and installation contract, this is a contract under which a principal engages a contractor to design, build, deliver and install the asset in order for it to be operational. EPCI contracts are often used for large-scale mining infrastructure such as mineral processing plants. EPCI contracts are complex because they encompass the design, detailed engineering and construction of infrastructure, including the supply of materials and services (for example, testing and installation) to ensure the smooth operation of the infrastructure.

Under an EPCI contract, the contractor may perform all the services itself; however, EPCI contracts usually give the contractor a right to subcontract part of the work. However, the contractor bears the project risk because most EPCI contracts are for a fixed price (irrespective of subcontractor agreements) and based on a schedule mutually agreed in the EPCI contract. The contract price paid by the principal to the contractor is usually paid in stages on the completion of certain project milestones.