667Rules for attributing surplus amount to earlier periods etcU.K.
(1)This section supplements section 666.
(2)An amount exempted under this Chapter for an earlier accounting period is reduced by the surplus amount only if that earlier accounting period ends not more than 6 years before the end of the accounting period in question.
(3)If the condition in subsection (2) is met in the case of more than one earlier accounting period, amounts exempted under this Chapter for later accounting periods are reduced in priority to earlier ones.
(4)If an amount exempted under this Chapter has been reduced under section 666 in respect of non-qualifying expenditure incurred in an accounting period, it may not be reduced again under that section in respect of non-qualifying expenditure incurred in a later accounting period.
(5)Such adjustments must be made (whether by way of the making of assessments or otherwise) as may be required in consequence of section 666(7).