This study examines how societal patience and risk-taking preferences shape small and medium-sized enterprises' (SMEs) voluntary audit demand, and how institutional quality moderates these relationships. Drawing on temporal self-regulation and signaling theories, we analyze 95,432 privately held SMEs across 64 countries (2006–2026). We find that societal patience (risk-taking) is positively (negatively) associated with voluntary audit uptake. Importantly, institutional quality symmetrically moderates both effects. Strong institutions amplify both the positive patience effect and the negative risk-taking effect, while weak institutions attenuate both. The results are robust to endogeneity, selection bias, omitted variables, and alternative specifications, with randomization placebo tests ruling out spurious correlations. This symmetric amplification pattern suggests that strong institutions amplify both patience and risk-taking effects rather than selectively constraining only undesirable behaviors. Our findings contribute to institutional theory and have direct implications for audit regulation design and stakeholder evaluation of governance practices across diverse contexts.