Contractors are picked at pre-qualification and judged at handover

Yes, and they should be. An integrated audit covers the shared requirements once, from context and leadership through competence, internal audit and management review, then tests the discipline-specific parts separately. It cuts audit days against three standalone audits and produces one surveillance date. Certificates are still issued individually, so a tender asking for one standard is answered with one document.

Usually not, but their work is inside your audit. As principal contractor you have to show how subcontractors were selected, what competence and training records you hold, how their method statements were approved and how their non-conformances were closed. Large clients increasingly require certification from major trade packages too. Where a subcontractor holds one, check the scope covers the work you engaged them for.

The auditor selects, not the contractor. The sample is drawn to cover the range of work, risk and geography, and normally includes at least one high-risk activity such as lifting, excavation or work at height. Head office is always audited. Sites reaching completion mid-cycle are replaced at the next surveillance visit, so the sample is never identical twice.

Sometimes, but treat that as secondary. Underwriters price on claims history and controls, and a certified safety system with real incident investigation records is evidence on the controls side. The direct commercial effect sits at pre-qualification, where certification is a pass or fail gate, and in disputes, where inspection records decide who pays for the rework.

The scope changes shape. Manufacturers are audited on production process control, incoming material verification, testing and factory production control, and for the European market on conformity marking with declared performance against a harmonised standard. Contractors are audited on site delivery instead. Get the scope wording exact, because a distributor is comparing your certificate against the product they intend to list.

Three years, with a surveillance audit every year. Surveillance is shorter than the initial audit and concentrates on what changed: new project types, new sites, incidents, previous findings and internal audit coverage. Miss the surveillance window and the certificate is suspended, which shows on the register. A suspended certificate reads worse in a pre-qualification review than no certificate at all.