Over the half century since Independence in most African states the UN Statistical Division has played an increasing role in getting member countries to standardise and streamline their data collection and in particular the definitions used for data collection. A key concept in censuses and surveys is the definition of household since this determines the units for which much data are collected and analysed, and thus influences the data which are the basis for many policies. In this paper we analyse the evolution of the UN household definition over this time period and what aspects of the household this definition appears to be trying to capture. Using detailed census and survey documentary data (from questionnaires, enumerator and supervisor manuals etc) for 4 African countries (Burkina Faso, Senegal, Uganda and Tanzania) we examine the extent to which each country has actually implemented this definition in different data collection activities over the last 50 years, highlighting differences between Anglophone and Francophone practice but also noting where country level idiosyncrasies and adaptations to local conditions are priorities. In a final stage perspectives provided from in-depth interviews with key informants from different levels within the hierarchy of statistical offices in each country, demonstrate the variability in the importance accorded to the UN harmonisation aims and the problems which arise when these standardised approaches interact with local norms and living arrangements.