50Completion of enquiry
(1)An enquiry is completed when WRA issues a notice (a “closure notice”) to the person who made the tax return stating—
(a)that the enquiry is complete, and
(b)the conclusions reached in the enquiry.
(2)A closure notice must either—
(a)state that in WRA’s opinion no amendment of the tax return is required, or
(b)make the amendments of the tax return required to give effect to WRA’s conclusions.
(3)Where a closure notice is issued which makes amendments of a tax return, the person who made the tax return may no longer amend it under section 41.
(4)The person who made the tax return must pay an amount, or additional amount, of devolved tax chargeable as a result of an amendment made by a closure notice before the end of the period of 30 days beginning with the day on which the notice is issued.