In the national accounts labour inputs are collected by industry. Homogenising means transforming labour inputs by industry into labour inputs by product. This homogenisation is done using mathematical techniques. The paper compares the results for two wellknown techniques (product technology and industry technology) and discusses the effects of homogenisation on Belgian data for the years 2000 and 2005. Labour inputs are detailed by gender and education level. An additional distinction is made between employees and self-employed. The paper proposes a solution for the negatives problem that arises when applying the product technology model in the case of self-employed workers. It also assesses the plausibility of results by showing the effects of homogenising on wage costs and value added per head as well as on the ranking of industries by education level. The product and the industry technology model yield significantly different results, most particularly for the employment use of wholesale and retail trade. The results of the product technology model are judged to be most plausible.