3For section 3 of that Act there shall be substituted the following section—
“3(1)Gas Levy shall be paid to the Secretary of State in respect of each period of three months ending on 30th June, 30th September, 31st December or 31st March in any year (in this section referred to as a “chargeable period”).
(2)It shall be the duty of any person liable to pay gas levy to deliver to the Secretary of State—
(a)within four weeks after the end of each chargeable period, a return for that period which complies with subsection (3) below; and
(b)within three months after the end of each year, a return for that year which so complies.
(3)A return under subsection (2) above for any chargeable period or any year shall show the quantity, expressed both by volume and as a number of therms, of gas to which section 1 above applies which was supplied to or won by the person concerned in that period or that year.
(4)Not later than six weeks after the end of any chargeable period a person who is liable to pay gas levy in respect of that period shall pay to the Secretary of State an amount equal to the amount of gas levy which would be due from him for that period if the amount due were calculated exclusively by reference to the return for that period.
(5)If the amount which, otherwise than by way of interest, falls to be paid by any person under subsection (4) above in respect of the chargeable periods in any year differs from the actual amount of gas levy due from that person in respect of those periods, then not later than four months after the end of that year the amount of the difference shall—
(a)where the former amount is greater, be repaid by the Secretary of State to that person; and
(b)where the latter amount is greater, be paid by that person to the Secretary of State.
(6)Where any amount falling to be paid under subsection (4) or (5) above is not paid within the period for payment specified in that subsection, that amount shall carry interest at the prescribed rate from the end of that period until payment; and in this subsection “paid” and “payment” include repaid and repayment, respectively.
(7)In this section “the prescribed rate” means the rate prescribed for the purposes of section 86 of the Taxes Management Act 1970.”