Section 83(1) of the Finance Act 2005 (c. 7) required securitisation companies to use UK generally accepted accounting practice as it stood at 31st December 2004 as the basis for tax computations for periods of account beginning on or after 1st January 2005 and ending before 1st January 2008. The application of section 83(1) was extended by the Securitisation Companies (Application of Section 83(1) of the Finance Act 2005: Accounting Standards) Regulations 2007 (S.I. 2007/3338) (“the principal Regulations”) to periods of account ending before 1st January 2017 in relation to companies to which the provision applied in a period of account ending before 1st January 2008, subject to a company electing that the extension did not apply.