This chapter adds to a young body of literature exploring the patterns of and motivations for the intra-EU mobility of non-EU migrants. As explanatory factors of these mobilities, recent studies point to the constrained access to work, networks and institutions in the country of residence. The role of children in onward mobilities has received little attention thus far. While offspring are generally theorised as a ‘binding’ factor, research suggests that children can also be central in onward-mobility decision-making. Parents take children’s specific needs and their hopes for their children’s future into consideration within the decision of onward mobility. Children can also move on their own account or stay put while their parents move again. We present a case study to unveil the dynamics within Somali families around the decision to move onwards to the UK. This provides a rich and suitable case, because of the relatively high onward-mobility rates and the great variety in family composition and characteristics. Using a mixed-methods design, we develop, test and contextualise theoretical expectations concerning the relationship between the timing of arrival of children in the host country and their onward migration, with or without their parents. In addition, we empirically address the expectation that independent migration is more common in larger families. A comparison with other young people of refugee background is provided to shed light on the particularities and generalities of our findings.