Thin capitalisation is a key concept in UK corporate tax, especially for groups that fund their operations through debt. It describes a situation where a company is financed with a relatively high level of debt compared to equity, often to take advantage of tax-deductible interest.
What Is Thin Capitalisation?
A company is said to be thinly capitalised when it carries more debt than it could realistically borrow on its own as an independent business. Because interest is generally deductible while dividends are not, groups can be tempted to load a UK company with intra-group debt to reduce taxable profits.
Why HMRC Takes an Interest
The UK’s transfer pricing rules require that intra-group borrowing reflects what would have been agreed between independent parties. Where a company is thinly capitalised, HMRC may disallow part of the interest deduction, treating the excess borrowing as something an unconnected lender would not have provided.
Managing the Risk
Groups can manage thin capitalisation risk by reviewing debt levels, interest rates and guarantees against arm’s length standards, and by keeping clear documentation. The Corporate Interest Restriction rules may also limit deductions separately, so both regimes need to be considered together.
How TaxDigit Can Help
Our Guildford-based team helps groups review intra-group financing and address thin capitalisation risk before it becomes a problem. Contact us to discuss your funding structure.
Thin Capitalisation: UK-Wide Corporate Tax Support
Thin capitalisation is a concern for groups across the United Kingdom, not just those near our Guildford head office. TaxDigit helps UK companies and international groups test whether their intra-group debt is at an arm’s length level and manage the transfer pricing risk that follows.
Our chartered certified accountants review your financing structure, model interest deductibility and help you document a defensible position before HMRC raises an enquiry. We act for clients UK-wide, remotely and on-site.
How we help with thin capitalisation
- Assessing whether a UK company is thinly capitalised on arm’s length terms
- Reviewing intra-group loan agreements and interest rates
- Modelling the impact of the Corporate Interest Restriction
- Preparing transfer pricing documentation to support interest deductions
- Advising on debt-to-equity structuring for new UK investment
HMRC explains the rules in its International Manual: HMRC thin capitalisation legislation guidance (INTM413090).
Frequently Asked Questions
What is thin capitalisation?
A company is thinly capitalised when it carries more debt than it could have borrowed as an independent business, often to maximise tax-deductible interest. UK transfer pricing rules can deny the excess deduction.
Why does HMRC scrutinise thin capitalisation?
Because interest is deductible while dividends are not, groups can load a UK company with intra-group debt to reduce taxable profits, so HMRC tests whether the borrowing is at arm’s length.
Can TaxDigit help if I am not based in Guildford?
Yes. We advise on thin capitalisation for clients UK-wide, remotely and from our Guildford office.