A certificate issued by the contractor to each n/s subcontractor with a copy to the principal agent/agents stating the date on which the subcontract works was substantially complete – to the extent that work by other subcontractors / the contractor to achieve practical completion can follow. The subcontractor remains liable for defects arising from the quality of his work for five years from the date of final completion – longer if a defect has occurred during this period

See: 6.1N-18.0; 5.0N-23.0; 4.1N-23.0