Tumour DNA and germline testing, based on DNA-wide sequencing analysis, are becoming more and more routine in clinical-oncology practice. A promising step in medicine, but at the same time leading to challenging ethicolegal questions. An important one is under what conditions individuals (patients and their relatives, research participants) should be recontacted with new information, even if many years have passed since the last contact. Based on legal- and ethical study, we developed a tool to help professionals to decide whether or not to recontact an individual in specific cases. It is based on four assessment criteria: (1) professional relationship (2) clinical impact (3) individual's preferences and (4) feasibility. The tool could also serve as a framework for guidelines on the topic.