Many bookmakers such as 888sport, Betfair, Ladbrokes and William Hill have offshore operations but these are largely for overseas customers since no tax is due on winnings of bets in the UK. Before 2001, a 10% levy was paid on bets at an off-course bookmaker (but none at a racecourse) and this could be paid "before" or "after" i.e. on the stake or the winnings, the proceeds going to the Horserace Totalisator Board. Many would advise you, as a tipster, to "pay the tax before" since it is a smaller amount, but mathematically it works out the same since arithmetical multiplication is commutative. This tax was abolished with the general reform of the gambling acts.