We examine the relative importance of audit firm-level versus audit partner-level styles in key audit matter (KAM) outcomes. We define style as stable within-firm (partner) similarities and between-firm (partner) differences in KAM reporting over time and across clients and industries with respect to the volume of KAMs, their topical diversity, and the linguistic manner in which they communicate KAMs to users. Using a sample of UK KAMs, we find that firms and partners have unique styles for KAM reporting volume, topical diversity, and communication. Partner-level styles are the locus of KAM reporting decisions, adding 10 to 19 percent improvement in explanatory power versus firms’ two to five percent. Partner demographics do not meaningfully explain KAM reporting outcomes. We find that partners make unique KAM reporting judgments, countering concerns that audit firms’ standardization will yield boilerplate KAMs, but lending credence to concerns that KAM reporting judgments may lack comparability across partners.