Calculate Corporation Tax Amount

By now, you might have adjusted the profitable tax figure by up to six times! If the profitable tax is £300,000 or less, then the tax rate is 21% (2010/2011) and 20% (2011/2012). Pro-rata this for months within your financial year that fall in each financial year.


As an example, if my limited company has profitable tax of £120,000. That is £10,000 per month. The company financial year starts in January. Hence three months fall in 2010/2011 and then nine months in 2011/2012. I therefore have a corporate tax bill of £24,300 which is 20.25% ie:

  • £6,300 [3 months * £10,000 * 21%] PLUS
  • £18,000 [9 months * £10,000 * 20%]


If the taxable profits is over £1,500,000 then you are very unlikely to need this site to help you. The calculation is as per the low tax company using the higher rates of 28% (2010/2011) and 26% (2011/2012).

For companies whose taxable profit falls between the two ie > £300,000K and < £1,500,000, the value is as per the highly profitable companies (28%, 26%) minus 7/400 [for 2010/2011] of the amount that the profitable tax figure is below of the upper limit.
For a £600,000 profit, all earned in 2010/2011, the corporation tax is £152,250 (25.38%) ie

  • £168,000 [28% * £600,000] minus
  • £15,750 [7/400 * (£1,500,000 - £600,000)].


That fraction “3/200” changes by tax year:

  • 2010/11 it is 7/400,
  • 2011/12 it is 3/200,
  • 2012/12 it is 1/100


All the details are in http://www.hmrc.gov.uk/rates/corp.htm. The column headed 2010 is for financial year 2010/2011. Hopefully, everything else will now make sense.