11(1)Subject to sub-paragraphs (4) and (6) below, every participator in an oil field shall, in the third month of each chargeable period and in each of the four succeeding months, make to the Board an advance payment of duty in respect of the field for that period.
(2)The amount of each payment shall be equal to one-fifth of the amount, if any, shown in the statement delivered by the participator under paragraph 10(1)(a) above as payable by him in respect of the field for the last chargeable period.
(3)The aggregate of the advance payments of duty made by a participator in respect of a field for a chargeable period—
(a)shall, to the extent to which it does not exceed the sum which sub-paragraph (1)(b) of paragraph 10 above requires him to pay when delivering his return for that period in respect of the field—
(i)discharge his liability to pay the whole or a corresponding part of that sum ; and
(ii)be treated for the purposes of sub-paragraph (4) of that paragraph as if it were, or were part of, a sum paid by him under sub-paragraph (1)(b) of that paragraph ; and
(b)shall, to the extent to which it exceeds the sum required to be paid as aforesaid, be repaid to him.
(4)If in any month in a chargeable period a participator in an oil field—
(a)has not delivered (otherwise than to the Secretary of State) any of the oil which has been won from the field and disposed of by him at any time in or before that month ; and
(b)has not relevantly appropriated any of the oil which has been so won by him at any such time,
he shall be entitled to withhold the advance payment of duty (if any) in respect of the field for that period which next falls to be made by him after the end of that month.
(5)An advance payment shall not be withheld by virtue of the conditions in sub-paragraph (4) above being fulfilled in any month unless a notice to that effect, in such form as the Board may prescribe, is given to the Board before the end of the next month and—
(a)where the Board are not satisfied with any such notice the powers conferred by paragraph 7 of Schedule 2 to the principal Act (production of accounts etc.) shall be exercisable as if the notice were a return under paragraph 2 of that Schedule ; and
(b)paragraph 8 of that Schedule (penalties) shall apply to an incorrect notice as it applies to an incorrect return under paragraph 2.
(6)No advance payment of duty shall be made in respect of the first chargeable period to which Part VIII of this Act applies or in respect of the first chargeable period for any oil field.