This study examines the integration of customary and modern audit practices in communal financial management within the Marind Indigenous community in Merauke Regency, South Papua. Although previous studies have discussed indigenous governance and accountability, limited research has explored customary audit mechanisms and their integration with modern auditing. This study addresses this gap by proposing an integrated audit framework that strengthens accountability while preserving customary values. A qualitative case study approach was employed involving 12 purposively selected informants, comprising four customary leaders, three communal financial managers, and five community members. Data were collected through semi-structured interviews, participant observation, and document analysis, and analysed using thematic analysis supported by open, axial, and selective coding. The findings reveal that customary audits rely on communal deliberation, witness testimony, customary sanctions, and the moral authority of customary leaders rather than documentary evidence. Accountability is maintained through collective participation, oral transparency, and social legitimacy. However, increasing administrative demands and limited financial documentation challenge the sustainability of customary governance. This study proposes an Integrated Customary Modern Audit Framework (ICMAF) that combines customary deliberation, witness-based verification, simple documentation, and formal accountability reporting. The framework contributes to indigenous accountability literature and offers practical guidance for developing culturally appropriate and sustainable communal financial governance.