If a shareholder-employee in your close company has an overdrawn current account (the company has effectively lent them money), you must either charge interest at the IRD prescribed rate or pay FBT on the deemed low-interest loan. This calculator works out the after-tax cost to the shareholder family under each option, using the current 5.77% prescribed rate (from 1 January 2026) and the 28% NZ company tax rate. The result tells you which path leaves more money in the family's pocket.
When a shareholder-employee draws money out of a close company beyond their salary, dividends, or repayment of loans owed to them, the resulting debit balance in their current account is effectively a loan from the company to the shareholder. Because the shareholder is also an employee, this is an "employment-related loan" under section CX 10 of the Income Tax Act 2007. If the loan is interest-free or charged at less than the IRD prescribed rate, the difference between the prescribed rate and the actual rate is a low-interest loan fringe benefit subject to FBT.
The company invoices the shareholder interest at or above the IRD prescribed rate (currently 5.77% from 1 January 2026). The interest is income to the company (taxable at 28%) and a payment by the shareholder. No FBT applies because the loan is no longer a low-interest loan. The interest must be either paid in cash or credited to (compounding) the current account; a notional journal with no economic effect is not enough.
Net family cost = interest amount × 28% (the company tax leakage on the interest income). The shareholder's payment is offset by the company receiving the same amount, so within the family unit the only cost is the tax paid on the interest as it passes through the company.
The company does not charge interest. It pays FBT on the taxable value, which is the balance × (prescribed rate − actual rate). At 63.93% single rate, FBT on a $50,000 interest-free loan for a full year at the 5.77% prescribed rate would be $50,000 × 5.77% × 63.93% = $1,844.39. The FBT itself is deductible to the company, generating a $516 tax saving, leaving a net family cost of $1,328.
The math always favours charging interest unless the shareholder cannot fund the payment. The reason is structural: FBT effectively taxes the same economic benefit (the deemed interest) at a much higher rate than the company tax that would apply to actual interest income. At the 63.93% single rate, the after-tax FBT cost is approximately 46% of the deemed interest amount; charging interest costs only 28%. The break-even FBT rate would be 39%, which means the alternate 49.25% FBT rate also makes charging interest the cheaper option.
| From | Rate |
|---|---|
| 1 January 2026 | 5.77% |
| 1 October 2025 | 6.29% |
| 1 July 2025 | 6.67% |
| 1 April 2025 | 7.38% |
| 1 October 2023 | 8.41% |
This calculator provides an estimate only. Always verify your treatment with a tax adviser or refer to ird.govt.nz. Charged interest must be commercially documented. Consider whether dividends, salary, or repayment of shareholder advances might better address the underlying overdrawn position.
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