“(1) If an officer 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 an 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 his or their opinion to be charged in order to make good to the Crown the loss of tax. … (3) Where the taxpayer has made and delivered a return under section 8 or 8A of this Act in respect of the relevant year of assessment, he shall not be assessed under subsection (1) above— (a) in respect of the year of assessment mentioned in that subsection; and (b) in the same capacity as that in which he made and delivered the return, unless one of the two conditions mentioned below is fulfilled. (4) The first condition is that the situation mentioned in subsection (1) above was brought about carelessly or deliberately by the taxpayer or a person acting on his behalf. (5) The second condition is that at the time when an officer of the Board— (a) ceased to be entitled to give notice of his intention to enquire into the taxpayer's return under section 8 or 8A of this Act in respect of the relevant year of assessment; or (b) informed the taxpayer that he had completed his enquiries into that return, the officer could not have been reasonably expected, on the basis of the information made available to him before that time, to be aware of the situation mentioned in subsection (1) above. (6) For the purposes of subsection (5) above, information is made available to an officer of the Board if— (a) it is contained in the taxpayer's return under section 8 or 8A of this Act in respect of the relevant year of assessment (the return), or in any accounts, statements or documents accompanying the return; … (8) An objection to the making of an assessment under this section on the ground that neither of the two conditions mentioned above is fulfilled shall not be made otherwise than on an appeal against the assessment. …”
“I do not require you to provide any information as it is all contained within the foreign pages of the return.”
“It was from finding the error within that claim it became apparent there was a similar error contained within the 2012-13 tax return.”
“[65] Our conclusion on this point, therefore, is that s 29(5) does not require the hypothetical officer to be given the characteristics of an officer of general competence, knowledge or skill only. The officer must be assumed to have such level of knowledge and understanding that would reasonably be expected in an officer considering the particular information provided by the taxpayer. Whilst leaving open the exceptional case where the complexity of the law itself might lead to a conclusion that an officer could not reasonably be expected to be aware of an insufficiency, the test should not be constrained by reference to any perceived lack of specialist knowledge in any section of HMRC officers. What is reasonable for an officer to be aware of will depend on a range of factors affecting the adequacy of the information made available, including complexity. But reasonableness falls to be tested, not by reference to a living embodiment of the hypothetical officer, with assumed characteristics at a typical or average level, but by reference to the circumstances of the particular case.”
“For the purposes of this Act a loss of tax or a situation is brought about carelessly by a person if the person fails to take reasonable care to avoid bringing about that loss or situation.”
“The test to be applied, in my view, is to consider what a reasonable taxpayer, exercising reasonable diligence in the completion and submission of the return, would have done.”