The Pensions Advisory Service (PAS) state that people who earn less than £95 per job undertaken they are not entitled to pension credits.
Staff in these circumstances are often filled by women, which means that thousands of women are missing out on a state pension.
The government has promised to make the pension system for fairer to women from 2010.
For more information on this story, visit: http://news.bbc.co.uk/1/hi/uk/8300369.stm