The journey through a doctoral candidature can be a challenging and emotional experience for both the candidate and their supervisors. Doctoral students are often known to experience “stuckness”, reach “brick walls” and experience “mental blocks” at various stages in their research. These barriers can prevent the progression or “learning leaps” of the candidate through key threshold research milestones of the doctoral degree. Supervisors typically take on the role of guide, coach and mentor throughout the process while enacting their conceptions of the research process. Identification of the threshold concepts and skills required of a postgraduate candidate can assist the developmental journey experienced by both students and their supervisors. Findings from an analysis of the guidance provided to potential and current doctoral students, a collection of milestones, skills and desirable competencies emerged. However, further analysis indicates that essential threshold concepts identified in the research literature are not in evidence on university websites. There appears to be a disconnect between the emphasis on procedural milestones on these sites, which are intended as guidelines for potential students, and essential research concepts and skills (that is, threshold concepts) that students require on the doctoral journey. Awareness of these transformative stages in a typical doctoral program of study may enable supervisors to assist their students to advance through these conceptual barriers. The research recommends that identification of the threshold concepts and skills required of a postgraduate candidate can assist the developmental journey experienced by both students and their supervisors.