Introduction Contemporary models of suicide have largely overlooked why a person at high risk for suicide attempts suicide at a specific time. We propose the construct of unacceptable loss thresholds (i.e., a person’s tolerance limit for a negative life event, which if violated results in an increase in suicide risk), which addresses many paradoxes in the literature related to suicide triggers. The aim of this paper is to provide preliminary proof of concept and to stimulate replication and further empirical study. Methods We recruited an online community sample of individuals with a suicide attempt history (n = 144). These individuals answered questions about the time leading up to their most recent suicide attempt. Results The majority (70.8% yes; 18.1% cannot remember; 11.1% no) reported creating a threshold of unacceptable loss, and that relatively small events were enough to trigger feelings that life was not worth living (63.9% yes; 30.6% maybe; 5.6% no). Further, the majority (57.6% yes; 21.5% yes, but only if asked; 20.8% - no) reported they would be willing to tell their therapist/doctor about their thresholds of unacceptable loss. Conclusion The construct of unacceptable loss deserves further empirical inquiry. Individuals contemplating suicide set them and if the loss occurs, it may trigger suicidal action in suicide ready individuals. Thresholds could provide risk assessment and safety planning data currently being overlooked.