Background There are statutory provisions relating to the notices and statements required upon an auditor ceasing to hold office. Section 18 and Schedule 5 of the Deregulation Act 2015 (DA 2015), which came into force on 1 October 2015, made a number of changes in relation to auditors, which include the statutory provisions dealing with the notices and statements required on an auditor ceasing to hold office. The amendments have effect in relation to financial years beginning on or after 1 October 2015. For the purpose of the notices and statements required on an auditor ceasing to hold office, the DA 2015 amended the Companies Act 2006 (CA 2006) to make a distinction between public interest companies and non-public interest companies (each being treated slightly differently), rather than the distinction between quoted companies and unquoted companies (again, each being treated slightly differently) which applied before the DA 2015 amended the CA 2006. For details of the relevant provisions in relation to financial years beginning before 1 October 2015,