(1)General betting duty is charged on a general bet made with a bookmaker.
(2)It is charged at the rate of 15% of the bookmaker's profits on general bets for an accounting period.
(3)The bookmaker's profits on general bets for an accounting period are the aggregate of—
(a)the amount of the bookmaker's ordinary profits for the period in respect of general bets (calculated in accordance with section 131), and
(b)the amount of the bookmaker's retained winnings profits for the period in respect of general bets (calculated in accordance with section 132).
(4)Where the calculation for an accounting period under subsection (3) produces a negative amount—
(a)the bookmaker's profits on general bets for the accounting period are treated as nil, and
(b)the amount produced by the calculation may be carried forward in reduction of the bookmaker's profits on general bets for one or more later accounting periods.