HMRC have now published official statistics on Tax receipts and the number of taxpayers in the UK.
Overall, total tax receipts by HMRC were £408,496 million in 2009-2010, down some £30,611 million since 2008-2009. Tax receipts peaked at £451,053 million in 2007-2008 before the economic crisis truly began. Total tax receipts are actual receipts of tax (generally on a cash basis) and are net of negative tax credits.
Comparing the total receipts of individual categories in 2009-2010 with the tax year 2007-2008, the most significant falls come from VAT which shows a 12.96% decrease (can be partially explained by the 15% rate for 1 year from January 2009), corporation tax with a fall of 22% and stamp duty receipts which have fallen 44% to £7,093 million in the last tax year. Income tax and CGT fell 7.1% in that period.
The number of taxpayers and registered traders also shows a decline since 2008-2009.
Full details of the statistics can be accessed here.