Energy users who don’t participate in efficiency and conservation programmes despite ongoing outreach are often referred to as ‘Hard-to-Reach’ (HTR). These individuals or organisations can include, e.g., low income or vulnerable households; renters; and small businesses. More effectively engaging HTR audiences is key to ensuring everyone benefits equitably from low-carbon energy transitions and related (policy) interventions. This is even more so the case in light of the COVID-19 pandemic, and the ongoing implications for energy use and affordability for the most vulnerable (and newly-vulnerable) members of our society.Within this context, the main purpose of this paper is to explore the extent to which HTR energy audiences have been impact...