Internally-defined ties such as friendship, trust, or closeness might enhance private transfers. The present study examines the role of these ties on top of the impact of genetic relatedness and legal family relations using families with varied access to filial support as a source of heterogeneity. We investigate, in addition to family support, financial and non-financial transfers received from unrelated individuals by mature adults in childless, dispersed (that is, with an adult child living at a significant distance from parents), and local families using the Survey on Health, Ageing and Retirement in Europe. We find that the structure of support given to mature adults indeed depends on internally-defined ties that are independent from family ties, controlling for other relevant factors. The positive impact on informal support of internally-defined ties concerns particularly, but is not limited to, non-financial support.