What Is Thin Capitalisation?
Thin capitalisation rules limit how much debt a company can use to reduce taxable profits. Learn why these rules exist and how they work.
Key Takeaways
- Thin capitalisation occurs when a company is funded with excessive debt relative to equity, often to maximise tax-deductible interest payments.
- Tax authorities impose thin capitalisation rules to prevent profit shifting through inflated interest deductions.
- Common approaches include fixed debt-to-equity ratios and earnings-based limits on interest deductions.
Why thin capitalisation matters
Interest on debt is typically tax-deductible, while dividends on equity are not. This creates an incentive for multinational groups to load subsidiaries with intercompany debt, generating large interest deductions that reduce local taxable profits. The interest flows to the lender (often a related entity in a low-tax jurisdiction), shifting profit out of the borrower's country. Thin capitalisation rules exist to prevent this.
How the rules work
There are two main approaches. Fixed ratio rules set a maximum debt-to-equity ratio, typically between 2:1 and 4:1. Interest on debt exceeding this ratio is not deductible. Earnings-based rules limit interest deductions to a percentage of EBITDA, commonly 30 percent, following OECD BEPS Action 4 recommendations. Nigeria uses a debt-to-equity ratio approach, while South Africa applies both methods.
Impact on business structuring
Companies establishing subsidiaries in countries with thin capitalisation rules must carefully plan their capital structure. Funding a new operation entirely with intercompany loans may seem attractive for tax purposes, but if the interest deduction is disallowed, the effective cost of funding increases significantly. The optimal structure balances tax efficiency with compliance risk and commercial reality.
Practical compliance steps
Review your intercompany financing arrangements against local thin capitalisation rules in each jurisdiction. Ensure debt-to-equity ratios remain within permitted limits. Document the commercial rationale for intercompany loans, including arm's length interest rates. Monitor earnings-based thresholds, which can fluctuate as EBITDA changes. Proactive management avoids unexpected tax adjustments and disputes.