- Got child benefit for a child under 16 (that changed to under 12 from 2010)
- Were unemployed and looking for a job. Usually you would be on Jobseeker's Allowance - but you may get credits even if you were not
- Were on employment and support allowance, or were eligible for it, or got statutory sick pay
- Received working tax credit
- Cared for someone who was sick or disabled
- Got maternity or paternity benefits
- Were male and did not work in the few years approaching the age of 65.
In exchange for one year's contributions you will get extra pension of £5.29 a week (£275 a year) from the date you pay. So the payback time for the cost of the contributions is three years - add nine months if you pay basic rate tax or two years if you pay higher rate tax. The pension you buy should rise by at least 2.5% a year until April 2024/25 and after that in line with earnings or possibly prices depending what a future government decides.