This study examines which economic and structural factors are associated with micro Swedish construction firms’ decision to choose voluntary audit after the abolition of statutory audit for the smallest limited companies. Drawing on agency theory, information asymmetry and stakeholder theory, the study analyses how firm characteristics relate to audit choice in a project-based industry with volatile cash flows and strong external dependencies. The sample covers Swedish limited liability companies in construction (SNI 41–43) below the statutory audit thresholds for the financial year 2024. All firms with voluntary audit (n = 232) are included and complemented with a random sample of non-audited firms (n = 1,524), yielding N = 1,756. Variables with extreme values are winsorized (1st/99th percentile) and hypotheses are tested using binary logistic regression.

The results show positive and significant associations between voluntary audit and ln (sales), board size, firm age and log total assets. Cash liquidity and profitability (ROA) are negatively and significantly associated with voluntary audit. Measures of external dependence and financial risk are not significant at the 5% level. Overall, the findings suggest that voluntary audit in micro construction firms is more closely related to governance complexity, maturity and economic scale, together with signs of economic pressure, than to the included proxies for external dependence and financial risk.