5(1)A claim for an accounting period of a company may be made after the end of 6 years from the end of the period if—
(a)the company has been assessed to corporation tax for the period before the end of 6 years from the end of the period,
(b)the company has appealed against the assessment, and
(c)the assessment has not become final and conclusive.
(2)No claim for an accounting period of a company may be made under this paragraph after the end of 6 years and 3 months from the end of the period.