“3(1 ) A claim under this Schedule may not be made more than 4 years after the end of the relevant tax year ”
“s 29 Assessment where loss of tax discovered 29(1) If an office of the Board or the Board discover, as regards any person (the taxpayer) and a year of assessment- (a) that any income which ought to have been assessed to income tax, or chargeable gains which ought to have been assessed to capital gains tax, have not been assessed, or (b) that any assessment to tax is or has become insufficient, or (c) that any relief which has been given is or has become excessive the officer or, as the case may be, the Board may, subject to subsections (2) and (3) below, make an assessment in the amount, or the further amount, which ought in their opinion to be charged in order to make good to the Crown the loss of tax”