The main contractor is the business that holds the primary contract with the Client and carries overall responsibility for delivering the project, coordinating the trades and subcontractors needed to complete it. In the US, the equivalent role is usually called the general contractor; the two terms describe the same function. On most UK projects involving more than one contractor, the main contractor is also appointed as the principal contractor under the Construction (Design and Management) Regulations 2015, taking on specific health and safety duties for the construction phase.
Worked example
On a £3m office refit, the main contractor holds the single contract with the client for the full £3m and is responsible for the finished building. It then lets a £400,000 mechanical and electrical Subcontract, a £250,000 fit-out subcontract and a £90,000 flooring subcontract, managing all three alongside its own labour on site. If the fit-out Subcontractor falls behind, the main contractor still owes the client a finished building on the agreed date, so the risk of subcontractor delay sits with the main contractor rather than passing straight to the client. The client deals with one party for the whole job; the main contractor deals with the complexity underneath.
Main contractor vs subcontractor
The main contractor holds the contract with the client and answers for the whole project. A subcontractor holds a contract with the main contractor, not the client, for one package of work such as groundworks, M&E or roofing, and the main contractor pays it, usually after a monthly application and with Retention held back. If a package runs late or is defective, the client claims against the main contractor, which then pursues the subcontractor.
Main contractor in the cost report
On the client's side, the main contractor's contract sum is usually the single largest line in the project budget. On the main contractor's own cost report, that same contract sum becomes the top-line revenue, against which every subcontract, direct cost and Overhead Allocation is measured to arrive at project margin. A main contractor's CVR is largely an exercise in tracking dozens of subcontract packages against one contract value. Retention held back from each subcontract, and the retention the client holds back from the main contractor in turn, both need tracking separately, since they are released on different dates tied to practical completion and the end of the defects period.
Related terms
Subcontractor, Subcontract, Client, Construction Manager, Quantity Surveyor (QS).
Main contractor software
Most main contractors track subcontract packages against the contract sum in spreadsheets until there are too many packages to keep them reliable. Planyard, our product, gives main contractors one view of every subcontract order, application, Variation and retention amount against the overall contract value, so the CVR comes from live figures. See our guide to main contractor software for how the options compare.