Previously, buyers paid 25 per cent on the first £10,000 or $20,000, followed by 20 per cent up to £250,000 or $500,000, and 12 per cent above that.
Under the new rates, buyers must pay 25 per cent on the first £25,000 or $50,000, followed by 20 per cent up to £500,000 or $1m, and 12 per cent thereafter.
Chief executive Bill Ruprecht said the change would “enhance our revenue stream and strengthen profit margins”.
As Sotheby’s try to focus on higher value works of art, it means that where they do sell lower-value items, they will charge higher rates of commission to do so.
Under the old rates, someone buying a $1m picture would have paid $163,000 premium, or an average of 16.3 per cent on the hammer price. Under the new rules this would rise to $202,500, or 20.25 per cent of the hammer price. Add VAT and a £1m picture becomes $46,413, or 4.64 per cent more expensive to buy.
However, Mr Ruprecht pointed out that for over 95 per cent of the lots Sotheby’s sell, the change would represent an increase of two per cent or less in the final price.