a construction subcontractor agreement is between a general contractor who holds an agreement with a client (“prime contract”) and a subcontractor to perform a service. before a contractor can hire a subcontractor, they first will need to make an agreement for services with a client. the contractor will need to coordinate with the subcontractor over the timing, responsibilities, and liabilities of their tasks as it pertains to the entire project. before most subcontractors will even talk about an agreement, they will need to see the plans between the contractor and the client. the subcontractor will need to know the exact specifications of what the client and contractor are trying to build.