NZ Terminal Tax Calculator
Reconcile your residual income tax (RIT) against PAYE/RWT credits and provisional instalments to see your final terminal tax top-up or refund, plus any UOMI and late-payment penalties if you're past the due date.
Due 2027-02-07.
IRD publishes current UOMI rates; default 8.97%.
Not sure if you need to file? Use our IR3 Filing Checker to find out.
Key rules at a glance
- Due date: 7 February following the tax year, or 7 April if filing through a tax agent with extension of time.
- Safe harbour: RIT under $60,000 — UOMI runs only from the day after the terminal tax due date, whether or not the instalments were paid on time. Pay the balance by the due date and there is no UOMI; pay late and it accrues from that date.
- Late payment penalties: 1% immediate + 4% if still unpaid seven days past the due date.
- UOMI: IRD's published late-payment rate (8.97% p.a. from 16 January 2026); credit rate when IRD owes you is lower. See every published UOMI rate, or compare a tax-pooling quote with that UOMI cost.
- Provisional tax trigger: If your RIT exceeds $5,000, you become a provisional taxpayer next year.
Already past the due date? The late filing penalty calculator works out the filing penalty, both late payment penalties and the interest day by day across every rate change in the period.
Frequently asked questions
What is terminal tax in New Zealand?
Terminal tax is the final income-tax top-up or refund after IRD reconciles your residual income tax (RIT) for the year against all credits — PAYE, RWT, imputation, and any provisional tax instalments already paid. Due 7 February in the year after year-end, or 7 April if you file through a tax agent with an extension of time.
What is residual income tax (RIT)?
RIT is the income tax you owe for the year before provisional tax is counted, minus PAYE, RWT, and imputation credits. It is the figure IRD uses to decide whether you must pay provisional tax next year (threshold $5,000) and whether UOMI applies ($60,000 safe-harbour threshold).
How does the $60,000 safe harbour work?
If your RIT for the year is under $60,000, you are in safe harbour, and it does not depend on the provisional instalments having been paid in full or on time. Safe harbour sets the date interest starts, not whether interest is charged: IRD charges use-of-money interest from the day after the end-of-year tax due date (7 Feb, or 7 Apr with a tax agent), so pay the balance by that date and there is no UOMI — pay it late and UOMI runs from the day after it. At RIT of $60,000 or more, interest instead runs from the day after the final instalment date, and any earlier instalment paid late or short attracts interest from the day after its own due date.
What is IRD's UOMI rate?
IRD publishes the use-of-money interest rate periodically (roughly floating Treasury bill rate plus a margin). The late-payment rate is 8.97% p.a. from 16 January 2026 (down from 9.89%), credit rate lower. Rates change — always check the current figure on ird.govt.nz before paying. This calculator defaults to the last published rate but lets you override it.
What penalties apply if I'm late paying terminal tax?
An initial 1% late-payment penalty applies the day after the due date, plus a further 4% if the amount remains unpaid seven days later. The old incremental 1%-per-month penalty no longer applies to income tax or provisional tax for the 2017-18 and later income years. UOMI runs separately from the relevant instalment or terminal date (depending on safe harbour) until the tax is paid in full.