The main rate, which is 12.5%, applies to trading income of companies.

Another change saw the single main rate of tax split into three.

Tax competition between jurisdictions reduced the main rate to 28%, with further reduction to 26% from April 2011.

In the financial year 2004-2005, approximately 39,000 companies paid corporation tax at the main rate.

From the first pay reference period starting on or after their 21st birthday, they become entitled to the main rate.

The main rate is 30 per cent for financial years starting on 1 April 2009, 2010 and 2011.

So far this year, the central bank has moved its main overnight rate up three times, from 2 percent, to 2.75 percent.

Banks followed suit, reducing their main rates to 13.5 percent.

Budget announcements of main rates and allowances for the tax year 2011-12.

The Bank of England, which cut rates seven times last year, left its main rate at 4 percent.