Although an Impact Assessment is not required where a predetermined formula, such as the rate of inflation, changes the rate of a tax, the Government have recognised that managing cash flow is a key concern for businesses in the current economic climate. This is why the Chancellor announced on 31 March that businesses will be allowed to pay just 2 per cent. of the RPI-linked 5 per cent. increase in their business rates bills in 2009-10. The remaining 60 per cent. can be deferred until 2010-11 and 2011-12.