53(1)An assessment made by virtue of paragraph 52 is not out of time under paragraph 46(1) (general six year time limit for assessments) if it is made—
(a)before the end of the accounting period following that in which the amount assessed was paid, or
(b)if later, before the end of the period of three months beginning with the day on which the Inland Revenue complete an enquiry into a relevant company tax return by the company concerned.
(2)Sub-paragraph (1) above is without prejudice to paragraph 46(2) (time limit for assessment in case of fraud or negligence).