The available estimates of the distribution of income tax liabilities can be found in table 3.2 “Distribution of median and mean income tax by age range and gender, 2004-05” on the HM Revenue and Customs website at:
http://www.hmrc.gov.uk/stats/income_distribution/menu-by-year.htm#32
Estimates of the distribution of national insurance contributions by age range and gender for 2004-05 are provided in the following table.
Age range Numbers paying NICs (000) Mean NICs (£) Numbers paying NICs (000) Mean NICs (£) Under 20 372 552 258 419 20 to 24 1,180 930 970 760 25 to 29 1,500 1,380 1,240 1,240 30 to 34 1,820 1,600 1,390 1,180 35 to 39 2,050 1,750 1,500 1,100 40 to 44 2,050 1,670 1,590 1,050 45 to 49 1,810 1,690 1,450 1,080 50 to 54 1,610 1,610 1,310 1,040 55-591 1,500 1,480 1,530 737 60 to 642 985 1,140 — — 65+ — — — — All ranges 14,870 1,500 11 ,250 1,010 1 Includes females that turned 60 at the end of the financial year but paid NICs as 59-year-olds for some proportion of the year. 2 Includes males that turned 65 at the end of the financial year but paid NICs as 64-year-olds for some proportion of the year. Notes: 1. This table is based on age at the end of the financial year. Individuals cease paying NICs when they reach state retirement age; this is 60 for females and 65 for males. 2. Figures are rounded so totals will not necessarily sum to their components. 3. Figures are UK primary accruals for 2004-05 net of rebates. They include Class 1 net, Class 2, Class 3 and Class 4 NICs. 4. The figures are estimated using: Annual survey of hours and earnings for 2004-05 for the Class 1 age distribution. Survey of personal incomes for 2003-04, uprated with earnings for 2004-05, for the self-employed age distribution. DWP contributions and qualifying years tables for 2002-03 for the Class 3 age distribution.