What Are the Thin Capitalisation and DDCR Rules?
Australia’s new thin capitalisation rules align with OECD BEPS Action 4 and apply to many multinational businesses, private groups, and wealthy entities with foreign control or significant outbound operations. (ato.gov.au) Alongside them, the Debt Deduction Creation Rules (DDCR) prohibit related-party or associate entities from structuring financial arrangements to create excessive deductible debt (e.g. via asset acquisition, distributions, or returns of capital) without tax consequences. (ato.gov.au)
Timing & Who’s Covered
- New thin capitalisation rules apply to income years starting on or after 1 July 2023. (ato.gov.au)
- DDCR apply to income years starting on or after 1 July 2024, to both existing and new domestic and international arrangements. (ato.gov.au)
- Entities with less than AUD $2 million in associate inclusive debt deductions may still benefit from a de minimis exemption. (ato.gov.au)
Fundamental Tests Under the New Rules
There are three main methods (“tests”) entities can use to calculate net debt deductions when subject to thin capitalisation rules:
| Test Type | Applicability | Key Features |
|---|---|---|
| Fixed Ratio Test | Default unless another is elected | Deductions limited to 30% of EBITDA; denied excess carried forward up to 15 years. (ato.gov.au) |
| Group Ratio Test | Entities in large groups | Based on worldwide group’s debt vs EBITDA; no carry forward usually. (ato.gov.au) |
| Third-Party Debt Test | Entities with external debt only | Related-party debt deductions largely denied; external debt allowed fully. (ato.gov.au) |
Practical Implications & Entity Setup
- Funding strategies: Using member-funded or related-party financing may result in lost deductions. External debt becomes more advantageous.
- Debt leverage: Excess debt may be carried forward under fixed ratio test, but only if thresholds met; group ratio or third-party tests avoid carry forwards.
- Restructuring: Asset transfers, dividends, or capital returns should be reviewed to avoid triggering DDCR consequences. Example: a parent entity distributing capital to reduce equity before incurring debt could be constrained.
Compliance and Reporting
- Large entities under Justified Trust programs are already under review for compliance with these rules; expect scrutiny of restructuring in response to thin capitalisation/DDCR. (ato.gov.au)
- Required to disclose relevant restructuring or selections via the Reportable Tax Position (RTP) schedule when filing. (ato.gov.au)
- Guidance and rulings are being published (e.g. PCG 2025/2; TR 2024/D3) to clarify the practical approach and help assess risk. (ato.gov.au)
Actionable Steps for Entities & Advisors
- Assess your existing debt structure and related interest rates. Are you using related-party debt? If so, what test (third-party vs fixed vs group ratio) provides the best outcome?
- For groups with international operations, compare the performance under each ratio test, considering carry forward or denial of deductions.
- Review any recent or planned restructuring, distributions, or returns of capital for potential DDCR exposure.
- Uplift internal documentation and ensure you have working papers to justify your chosen test—especially in audits under Top 100 or Top 1,000 schemes.