Betting Duty Mr. Greenway asked the Chancellor of the Exchequer by what percentage the off-course general betting duty would have to be increased in order to offset the abolition of the on-course general betting duty or a reduction of the on-course general betting duty by 2 per cent. Mr. Hayhoe The Current off-course rate of general betting duty would have to go up by 0·5 and 0·25 percentage points respectively.