Last year nearly 10% of all taxes came from duty on tobacco, alcohol, gambling, vehicle excise duty and fuel.
53p on a pint of beer, £8.54 on a bottle of whisky, and 75% of the price of cigarettes and 63% of the price of petrol is tax.
The number of people smoking has been falling, mileage rates for cars and vans has fallen for the last four years, and alcohol consumption, despite news headlines, has been going down since 2002.
All this means as less duty is being paid and revenue tax receipts for these are in decline - which OBR see as "an unannounced tax cut."
Expect other means of raising tax to rise to claw back this lost revenue as people drive less, drink less and continue to give up smoking - all good for them but bad for the Treasury.