Limitation on the deductibility of interest

income tax 1Author: Mike Betts, Partner Grant Thornton Cape

The February edition of e-taxline, Ignore 1 January 2015 tax changes at your peril, dealt with some important amendments to tax legislation that came into effect on 1 January and 1 March 2015. Another amendment that came into force on 1 January 2015 and requires careful consideration is contained in section 23M of the Income Tax Act (’the Act’) and deals with limitations on interest deductions for certain loan transactions.

Specifically, if a resident taxpayer (the debtor) borrows funds from another entity (creditor), but the creditor is not liable for tax on the interest in South Africa and the parties are in a controlling relationship with each other, then the debtor’s interest deduction for tax purposes may be limited.

A ‘controlling relationship’ is defined as one where a person directly or indirectly holds at least 50% of the equity shares in a company or can exercise at least 50% of the voting rights in that company.

This limitation on the deductibility of interest serves as an effective transfer pricing tool, as it is intended to apply to creditors who are non-residents enjoying the exemption from income tax on the interest received in terms of section 10(1)(h).

The provisions of section 23M can also apply where:

  • the creditor is not in a controlling relationship with the debtor but the amount advanced to the debtor was obtained from a person who is in a controlling relationship with the debtor;
  • the debtor is a non-resident who owes an amount which is effectively connected with a permanent establishment from which it operates in South Africa.

However, the provisions of section 23M do not apply where:

  • the interest incurred by the debtor is included in the net income of the creditor and the creditor is a controlled foreign company;
  • the interest is disallowed in terms of section 23N, which limits interest deductions arising as result of reorganisation and acquisition transactions;
  • the interest paid to the non-resident creditor is subject to withholding tax on interest (careful consideration must be given to the period between 1 January 2015 when section 23M became effective, and 1 March 2015 when the withholding tax on interest was introduced);
  • the creditor’s advance to the debtor emanated from funds that were granted by a foreign bank that is not in a controlling relationship with the debtor and the rate of interest applied to the loan does not exceed the official rate defined in paragraph 1 of the Seventh Schedule to the Act, plus 100 basis points;
  • certain linked units acquired by long-term insurers, pension funds or provident funds before 1 January 2013 (but only up to 31 December 2015).


Where section 23M applies, the amount of interest incurred on the loan that may be deducted is determined by a specific formula. Any interest paid that is not deductible in one tax year can be carried forward for further consideration in a subsequent tax year.

The details of the formula and the calculations associated therewith are too extensive to incorporate in this article but any taxpayer who has borrowed funds from a non-resident who is a controlling shareholder or, in whom the taxpayer itself holds a controlling interest, is encouraged to contact Grant Thornton for assistance in determining whether or not the provisions of section 23M apply to the situation in question.