The planned rise in the small companies' tax rate to 22% will be deferred until 2010-11, the chancellor announced today. In his last pre-Budget report before the general election, Alistair Darling said that the corporation tax rate for companies with profits of less than £1.5m would be frozen at 21% until April 2011. But John Whiting, tax policy director at the Chartered Institute of Taxation, said the decision still left 'small businesses up in the air'. He added: 'We have long argued that what is needed is a holistic review that aims to set out a general plan for taxing small businesses (incorporated and unincorporated) rather than leaving the prospect of higher tax rates up in the air and trying to block perceived abuses with ever more complex rules that are administratively burdensome. 'It's time for a full review of small business taxation.' Meanwhile, the government will extend the temporary increase in the threshold for empty property relief for a further year. For 2010-11, empty commercial properties with rateable values up to £18,000 will be exempt from business rates, continuing the exemption for an estimated 70% of empty properties. Separately the chancellor unveiled a reduced 10% corporation tax rate on income that stems from patents in the UK. Whiting described the move as 'a modest but welcome step in the right direction'. He added: 'The UK needs to have a tax system that hangs out the welcome sign for patents, rather than seeming to encourage the use of jurisdictions such as the Netherlands with their generous systems for such income.'