Audit fees, as a reflection of the auditor’s effort, perceived complexity, and risk assessment, can be influenced by a firm’s financial and credit structures. Among these, debt maturity structure and credit rating are considered key indicators of a company's financial position, potentially shaping auditors’ professional judgment regarding audit risk and, consequently, the level of audit fees. Moreover, the corporate life cycle, through its impact on the informational, structural, and financial characteristics of firms, may moderate these relationships. This study aims to examine the effect of debt maturity structure and credit rating on audit fees, with a particular focus on the moderating role of the corporate life cycle. The research is applied in nature and follows a descriptive-correlational approach. The statistical population includes all firms listed on the Tehran Stock Exchange from 2016 to 2023. After applying specific screening criteria, a final sample of 166 firms was selected. Data were collected from official financial sources and analyzed using multivariate regression models. The findings indicate a significant positive relationship between debt maturity structure and audit fees, and a significant negative relationship between credit rating and audit fees. Furthermore, the corporate life cycle positively moderates the relationship between debt maturity and audit fees, and negatively moderates the relationship between credit rating and audit fees. These results highlight the combined importance of financial, credit, and lifecycle-related factors in auditors’ risk assessments and audit fee determinations, offering valuable insights for auditors, financial analysts, and regulatory policymakers.