Final Certificate is when the defects liability period has come to an end/construction contract has ended.
It is issued by the architect at the end of the defects liability period.
The end of the construction contract and final payment due to the contractor. The remaining security is released to the contractor (by the owner).
The contractor is obliged to rectify any defects, even if the DLP has ended (Clause M14.1) – so long as they have been identified during the DLP and are due to poor workmanship (not wear and tear).
Architect to clarify if the defect was noted during the DLP or after (if within the DLP period, contractor is obliged to rectify, even after FC). If noted after FC, the owner should refer to the Home Warranty Insurance policy and can usually claim for damages in court.
The client’s agreement with the owner has ended after FC, therefore they longer have any more obligations, nor can they issue any further instructions.