"…(3) Subject to this section, an inspector may, for the purpose of enquiring into the tax liability of any person ("the taxpayer"), by notice in writing require any other person to deliver to the inspector or, if the person to whom the notice is given so elects, to make available for inspection by a named officer of the Board, such documents as are in his possession or power and as (in the inspector's reasonable opinion) contain, or may contain, information relevant to any tax liability to which the taxpayer is or may be, or may have been, subject, or to the amount of any such liability; and the persons who may be required to deliver or make available a document under this subsection include the Director of Savings. … (6) The persons who may be treated as "the taxpayer" for the purposes of this section include a company which has ceased to exist and an individual who has died; ... (7) Notices under subsection (1) or (3) above are not to be given by an inspector unless he is authorised by the Board for its purposes; and— ( a ) a notice is not to be given by him except with the consent of a General or Special Commissioner; and ( b ) the Commissioner is to give his consent only on being satisfied that in all the circumstances the inspector is justified in proceeding under this section. (8) Subject to subsection (8A) below, a notice under subsection (3) above shall name the taxpayer with whose liability the inspector (or, where section 20B(3) below applies, the Board) is concerned. (8A) If, on an application made by an inspector and authorised by order of the Board, a Special Commissioner gives his consent, the inspector may give such a notice as is mentioned in subsection (3) above but without naming the taxpayer to whom the notice relates; but such a consent shall not be given unless the Special Commissioner is satisfied— ( a ) that the notice relates to a taxpayer whose identity is not known to the inspector or to a class of taxpayers whose individual identities are not so known; ( b ) that there are reasonable grounds for believing that the taxpayer or any of the class of taxpayers to whom the notice relates may have failed or may fail to comply with any provision of the Taxes Acts; ( c ) that any such failure is likely to have led or to lead to serious prejudice to the proper assessment or collection of tax; and ( d ) that the information which is likely to be contained in the documents to which the notice relates is not readily available from another source. (8B) A person to whom there is given a notice under subsection (8A) above may, by notice in writing given to the inspector within thirty days after the date of the notice under that subsection, object to that notice on the ground that it would be onerous for him to comply with it; and if the matter is not resolved by agreement, it shall be referred to the Special Commissioners, who may confirm, vary or cancel that notice."