The Companies Act 2006 reformed and restated company law in the UK, replacing the Companies Act 1985, with final provisions implemented on October 1, 2009. Key changes include the modernization of company law, the introduction of new director duties, relaxed requirements for private companies, and modifications regarding financial information and auditor responsibilities. Accountants must be aware of new forms, penalties for late filings, and the implications of new rules for issuing shares and director loans.