Prequalification is the screening a general contractor does before trusting a subcontractor with a scope — reviewing their financials, bonding capacity, safety record (EMR), references, and relevant experience. It answers a simple question: can this sub actually deliver this work without putting the job at risk?
Good prequalification prevents the most expensive buyout mistake: awarding to a low bidder who then defaults, walks off, or can't staff the work. It's the risk-management front end of buyout.