The concept of the Daily Urban System (DUS) has gained relevance over the past decades as the entity to examine and explain the functionality of the urban landscape. Daily Urban Systems are usually defined and measured by the strength of commuter or shopper flows between the nodes of the system. It is important to realize that these Daily Urban Systems are the accumulated pattern of individuals making frequent, recurring trips to other localities than their own. Understanding the microeconomic decisions behind these spatial interactions will help in assessing the functional and spatial structure of DUS. In this paper is explored how, based on Dutch empirical data, the individual household’s spatial interactions shape the daily urban system and how the destination of these interactions correlates with personal and spatial variables and motives for interaction. The results show that the occurrence of non-local spatial interactions can be explained by the size-based Christallerian hierarchy of the localities of residence, but that it is the regional population – or market potential – that explains and moderates the sorting of households and the intensity and direction of their spatial interactions in the DUS, matching agglomeration theory.