Background: Families living in poor socio-economic circumstances, already confronted with social and health inequalities, are often not reached by family-based addiction prevention services. Besides quantitative models and health literacy approaches, qualitative research is lacking that could shed light on the exact circumstances and processes that lead to hindered addiction prevention service uptake by these families. Drawing on the concept of candidacy, we therefore reconstructed how socio-economically deprived parents and their (pre)adolescent children in the German-speaking part of Switzerland (non-)identified their candidacy for family-based addiction prevention services.Methods: Following grounded theory, we collected and analysed data in an iterative-cyclical manner using theoretical sampling and theoretical coding techniques. Sixteen families with children aged 10–14 years were interviewed in depth (parent/s and child separately). All but one family lived below the at-risk-of-poverty threshold.Results: Socio-economically deprived families’ modes of recognizing and handling problems in everyday life were found to be core phenomena that structure the process towards (non)identification of candidacy for family-based addiction prevention services. Four modes anchored within socio-demographic resources were found: Families with mode A perceived their current life situation as existentially-threatening and focused daily coping on the main pressing problem. Others (mode B) perceived prevalent multiple problems as normal (now); problems were normalized, often not recognized as such. In mode C families, problems were pragmatically recognized at a low threshold and pragmatically dealt with, mostly within the family. In mode D families, problems were constantly produced and dealt with early by the worried and anxious parents monitoring their child. From modes D to A, vulnerability increased concerning non-identification of candidacy for family-based addiction prevention services. Further, thematic relevance of addiction prevention, past experience with offers, integration in systems of assistance, strategies to protect the family, and families’ search for information influenced whether identification of candidacy took place.Conclusions: Socio-economically deprived families differ in modes of problem construction and handling in everyday life; this differently opens up or closes routes to family-based addiction prevention. Addiction prevention practice should build on a bundle of diverse strategies for outreach to these families, stressing especially interventions on the structural and environmental level.