Section 155 | Time limit for claiming relief
From legislation.gov.uk
(1)So far as a claim for loss relief against relevant miscellaneous income concerns the amount of the loss for a tax year, it must be made not more than 4 years after the end of the tax year.
(2)But—
(a)the question whether, and
(b)if so, how much,
loss relief against relevant miscellaneous income should be given for a tax year may be the subject of a separate claim made not more than 4 years after the end of the tax year.