Children are seldom accounted for in household behavioural models. They are usually assumed to have neither the capacity nor the power to influence the household decision process. The literature on collective models has so far incorporated children through the "caring preferences" of their parents or has treated them as household public goods [Bourguignon (1999); Blundell et al. (2005)]. This paper seeks to determine whether children of a certain age are decision-makers. We focus on the decision-making process within households composed of two adults and one child of at least 16 years of age. We first summarize the main restrictions that have been proposed to test the collective model in the context of multiple decision-makers [Chiappori and Ekeland (2006)]. We also show how a minimal number of decision-makers can be inferred from parametric constraints. Second, we apply these tests on data drawn from a series of U.K. Family Expenditure Surveys. Our results show clear evidence that it may be incorrect to assume that daughters and children aged between 16 and 21 are not full members influencing the household decision-making process.