A claim under section 225ZB must be made on or before the first anniversary of the normal self-assessment filing date for Year 1.

If the profits of a tax year are to be adjusted or further adjusted in accordance with this Chapter after an assessment for that tax year has become final and conclusive, any assessment or repayment or discharge of tax that is necessary to give effect to this Chapter must be made.

But repayment or discharge of tax is due only if a claim for it is made.