Section 255 | Further rules about allowable deductions
From legislation.gov.uk
(1)An amount may not be deducted more than once under section 254.
(2)A deduction under that section of a loss must be made from post-cessation receipts charged for an earlier tax year in preference to those charged for a later tax year.
(3)But this does not authorise the deduction of a loss from post-cessation receipts charged for a tax year before the tax year in which the loss is made.
(4)No deduction may be made under section 254 from any amount that is treated as a post-cessation receipt under—
(a)section 248(4) (debts paid after cessation), or
(b)section 250 (receipts relating to post-cessation expenditure).