PhD researchers are increasingly working in non-academic sectors, garnering interest in the extent to which doctoral education is relevant for careers beyond academia. Writing, arguably the most important and challenging activity PhDs must master, is a skill also coveted in the knowledge economy, required of employees across labour sectors. Using the concept of genre knowledge to frame how genres are performed in various situations, this exploratory qualitative study examines the perceptions of UK PhD holders in non-academic posts regarding the similarities and differences between academic and non-academic genres and the relevance of their PhD writing skills to their workplace writing. Findings suggest that PhD researchers' time and investment in academic writing during the degree leads to an understanding of how genres work -- knowledge that allows PhDs to adjust to writing in new situations.