HMRC – UK local tax authorities published recently “Income tax statistics and distributions”

Income Tax is an annual tax on an individual's income for a tax year (6 April to the 5 April the following year). It is the UK Government’s largest single source of tax revenue. For this reason UK Statistics Authority prepared a large and useful statistics based on this factor. Test.

The statistics aim to provide the taxpayers with more information on the current situation and to systematize and organize important information in one place. HMRC produce Income Tax statistics both on a liabilities and receipts basis:
Income Tax liabilities - http://www.hmrc.gov.uk/stats/income_tax/liabilities-april2011.pdf
Income Tax receipts - http://www.hmrc.gov.uk/stats/income_tax/it-stats-apr11.pdf

Liabilities are amounts of tax due on incomes arising in a given tax year, whereas receipts show amounts paid and collected in a given year. Due to lags in the payment of Income Tax, particularly that collected via Self Assessment, and other reasons, statistics on Income Tax liabilities will not match those for receipts.

If you require statistics about how much tax is actually paid and collected by HMRC in any given tax year, or information on how the tax has been collected, then you should look at statistics on Income Tax receipts.
The nature of how Income Tax is collected means it is not possible to analyse Income Tax receipts by taxpayer characteristics, for example, by taxpayer’s marginal tax rate, age or gender. However, these analyses are possible through modelling of Income Tax liabilities based on a representative sample of taxpayers using administrative data.
If you require detailed breakdowns of income taxpayer numbers and the distribution of tax liabilities across taxpayers and tax bands, then you should look at statistics on tax liabilities.
HMRC also produce detailed statistics on taxpayer incomes - http://www.hmrc.gov.uk/stats/income_distribution/menu.htm