“(1) An enquiry under section 12AC(1) of this Act is completed when an officer of the Board by notice (a "closure notice") informs the taxpayer that he has completed his enquiries and states his conclusions. In this section "the taxpayer" means the person to whom notice of enquiry was given or his successor. (2) A closure notice must either- (a) state that in the officer's opinion no amendment of the return is required, or (b) make the amendments of the return required to give effect to his conclusions. (3) A closure notice takes effect when it is issued. (4) Where a partnership return is amended under subsection (2) above, the officer shall by notice to each of the partners amend- (a) the partner's return under section 8 or 8A of this Act, or (b) the partner's company tax return, so as to give effect to the amendments of the partnership return. (5) The taxpayer may apply to the tribunal for a direction requiring an officer of the Board to issue a closure notice within a specified period. (6) Any such application is to be subject to the relevant provisions of Part 5 of this Act (see, in particular, section 48(2)(b)). (7) The tribunal shall give the direction applied for unless satisfied that there are reasonable grounds for not issuing a closure notice within a specified period.”