(1)Only winnings in the form of money are to be taken into account when determining for the purposes of this Chapter what are winnings on a bet.
(2)For those purposes, winnings on a bet include—
(a)the return of a stake on the bet, and
(b)any winnings on the bet held in an account for a person (“P”) if P is notified that the amount is being held in the account and may be withdrawn by P on demand.
(3)Winnings on a bet for which no stake money fell due are to be ignored for the purposes of any calculation under this Chapter.
(4)The Commissioners may by regulations make provision as to when, for the purposes of any calculation under this Chapter—
(a)winnings are to be treated as paid or provided, and
(b)expenditure on winnings is to be treated as incurred.