Many interventions in public health and related specialties are complex and challenging to assess. These interventions can have interacting components at several levels, with multiple and variable outcomes that require sophisticated assessments and analyses. Understanding randomised studies of these complex UPSCaLE (pUblic health, Psychology, Social work, CriminoLogy, and Education) interventions requires detailed reports of the interventions tested and methods used to assess them; however, reports of these trials often omit important information. Poor reporting hinders proper critical appraisal and synthesis of trials in systematic reviews, thereby impeding the effective transfer of research evidence to policy and practice decision-making. The CONSORT statement is a guideline for reporting randomised trials that has versions for reporting cluster, pragmatic, and non-pharmacological intervention trials. Despite improvements in reporting of these trials in medical disciplines, several studies have shown persistent deficiencies in the reporting quality of randomised studies of UPSCaLE interventions. Several researchers have suggested developing a new CONSORT extension for UPSCaLE interventions because of their unique and complex features, which is the objective of this multiphased project.