Problem definition: Trustworthy partners in procurement and service relationships are an asset. How can organizations discern trustworthy from untrustworthy partners, especially early on, so as to not waste time or resources on bad relationships? Academic/Practical Relevance: Prior studies have taken the perspective that, in most cases, organizations cannot perfectly know a partner's trustworthiness, but also that organizations often have some evidence of a partner's trustworthiness, even before interacting. We also adopt this perspective and argue a qualitative study is needed to understand how people use evidence to discern a partner's trustworthiness and how initial perceptions effect the trajectory of the relationship. Methodology: We conduct an interview-based study of how people discern trustworthy partners in a setting where doing so is challenging: the education sector. K-12 schools must choose outside partners to rely on for resources or services the school cannot afford. Potential partners are numerous and of variable trustworthiness. We focus data collection and analysis on how people's beliefs about a partner's trustworthiness initially form and influence the relationship over time. Results: We find people use contextual factors as evidence of a potential partner's trustworthiness, such as the partner's institutional affiliations, physical proximity, relationships with other schools, or other organizational characteristics. Sometimes the evidence indicates a partner acts intrinsically trustworthy, regardless of the contextual conditions. In other cases, the evidence indicates a partner acts contextually trustworthy, meaning partners follow through contingent on contextual conditions. Intrinsically trustworthy partners widely provide standardized resources or services. Contextually trustworthy partners provide the competitive advantage: customized resources that are not easily accessible by other schools. Yet, these partners also involve greater risk, particularly early on. When people perceive this risk, they initiate with small, low-stakes requests to explore the potential upside of the relationship while minimizing the potential downside. Managerial Implications: People in organizations identify trustworthy partners by paying attention to contextual factors, which helps them determine if a partner acts trustworthy independent of context or conditional on context. Intrinsically trustworthy partners are lower risk but provide standard resources, whereas contextually trustworthy partners are higher risk but provide customized resources.