This study investigates the relationship between corporate tax avoidance and the cost of debt, focusing on the moderating effects of institutional and managerial ownership in the Iranian capital market. Using a sample of non-financial companies listed on the Tehran Stock Exchange over the period 2015–2023, we examine whether ownership structure influences creditors’ perception of risk associated with tax avoidance activities. The results indicate a significant positive relationship between tax avoidance and cost of debt, suggesting that lenders demand higher returns when firms engage in aggressive tax strategies due to increased information asymmetry and potential reputational and regulatory risks. Furthermore, both institutional ownership and managerial ownership play important moderating roles. Higher levels of institutional ownership weaken the positive association between tax avoidance and cost of debt, consistent with effective monitoring by sophisticated investors. Managerial ownership also negatively moderates this relationship, though the effect is stronger at moderate levels of ownership. The findings are robust to alternative measures of tax avoidance (ETR and BTD) and different econometric specifications. This research contributes to the literature on tax avoidance and corporate governance in emerging markets and provides practical implications for managers, creditors, and policymakers in Iran.

Tax Avoidance Cost of Debt Institutional Ownership Managerial Ownership Moderating Effect Corporate Governance Tehran Stock Exchange