A Letter of Agreement (LOA) is a written document that formalizes responsibilities, scope, and expectations between parties involved in a study or trial activity.
LOAs are commonly used to document arrangements with service providers, consultants, laboratories, or participating departments when a full contract is not required. In clinical research, an LOA helps establish accountability for deliverables such as data handling, specimen processing, monitoring support, or regulatory coordination. Clear LOA terms support auditability by showing who is responsible for specific tasks and how oversight will occur. Well-maintained LOAs reduce operational ambiguity and support compliance with delegated responsibility expectations under GCP.