NZ Late Filing & Late Payment Penalty Calculator
Filed your IR3 late, paid a tax bill late, or both? Enter what you owed and when you paid to see the late filing penalty, the 1% and 4% late payment penalties, and the use-of-money interest IRD charges on top — with the interest split across every rate change in the period.
The terminal tax, provisional tax instalment or reassessed amount that was still outstanding on the due date — not your whole year's tax bill.
Terminal tax is due 7 February, or 7 April on a tax agent's list. Provisional instalments fall on 28 August, 15 January and 7 May. When the date lands on a weekend or public holiday, IRD moves it to the next working day.
Interest runs to the day the balance clears, so a later date costs more.
The three charges, and how they differ
1. Late filing penalty — a flat amount
Under section 139A(3) of the Tax Administration Act 1994 the penalty for filing an annual income tax return late is $50 where net income is below $100,000; $250 where net income is $100,000 to $1,000,000 (both inclusive); $500 where net income is above $1,000,000. IRD charges it only on the IR3 and IR4 returns, and only after giving at least 30 days' notice that the return is late — file inside that window and the penalty is not charged. IRD initially charges the $50 amount and adjusts it once your return shows your actual net income for the year.
2. Late payment penalties — 1% then 4%
Section 139B(2)(a) adds 1% of the unpaid tax the day after the due date. If anything is still outstanding at the end of the sixth day after that — the seventh day after the due date — a further 4% is added, calculated on the amount still to pay, which by then includes the 1%. So on $10,000 of unpaid tax the two penalties come to $504, not $500.
The old incremental 1%-a-month penalty in section 139B(2)(b) no longer applies to income tax or provisional tax for the 2017-18 and later income years, so for a modern income tax debt the penalties stop growing after day seven. Interest does not.
3. Use-of-money interest — the part that keeps running
Interest is charged from the day after the original due date until the balance clears, at IRD's published underpayment rate — 8.97% a year from 16 January 2026. It is simple daily interest, so it does not compound, and IRD charges it on the outstanding tax including penalties where that balance is more than $100. See every published UOMI rate and its effective date.
What this calculator does not model
- Part payments. The whole balance is assumed unpaid until the payment date you enter. Paying in instalments reduces the interest from each payment onwards.
- Shortfall penalties. Penalties of 20% to 150% for not taking reasonable care, gross carelessness, an abusive tax position or evasion depend on IRD's assessment of your behaviour and are not included here.
- The provisional tax safe harbour. If your residual income tax is $60,000 or less and you paid the standard uplift at each instalment on time, no UOMI applies to the terminal-tax shortfall. Check that first with the terminal tax calculator.
- Remission and instalment arrangements. IRD can remit penalties and interest in some circumstances, and setting up an instalment arrangement can stop further penalties.
- Other return types. GST late filing is $50 on the payments basis and $250 on the invoice or hybrid basis; employment information is $250 a month. This calculator covers the income tax return penalty.
If you are already late
File the return first, even if you cannot pay. The filing penalty is charged for the missing return, not the missing money, and IRD's 30 days' notice means a return filed promptly after the reminder attracts no filing penalty at all. Once the return is in, the remaining exposure is penalties and interest on the tax, which you can reduce by paying as much as you can as early as you can.
If cash flow is the problem, an instalment arrangement through myIR can stop further penalties accruing, and tax pooling providers can buy back-dated tax credits that offset a missed instalment date at less than IRD's UOMI rate. Not sure whether you had to file at all? The IR3 filing checker settles that in a few questions, and the tax deadlines page lists every IRD due date for the year.
Frequently asked questions
How much is the IRD late filing penalty?
It is a flat amount set by your net income for the year: $50 where net income is below $100,000; $250 where net income is $100,000 to $1,000,000 (both inclusive); $500 where net income is above $1,000,000. IRD only charges it on the IR3 individual and IR4 company income tax returns, and section 139A(5) of the Tax Administration Act 1994 requires at least 30 days' notice first — if you file within that window, no penalty is charged.
What are the late payment penalties?
An initial 1% of the unpaid tax is added the day after the due date. If any of it is still owing at the end of the seventh day after the due date, a further 4% is added — calculated on the tax plus that initial 1%, so the two do not simply add to 5%.
Does IRD still charge 1% a month on top?
No, not for income tax. The incremental 1%-per-month late payment penalty was removed for income tax and provisional tax for the 2017-18 and later income years, and for GST periods ending after 31 March 2017. It still applies to other tax types and to older debt, so an old balance can carry it.
How much interest does IRD charge on late tax?
From 16 January 2026, 8.97% a year, calculated daily and not compounding, from the day after the due date until the balance is paid. IRD charges it on the outstanding tax including penalties, where that balance is more than $100. Where the overdue period spans a rate change, each stretch is charged at the rate in force at the time.
What is a late payment grace period?
If it is your first late payment in a two-year period, IRD may give you a grace period and a new due date before charging the penalties. The grace period suspends the penalties but not the interest — and if you miss the new due date the penalties are charged from the original due date after all.
Can IRD write off the penalties?
Sometimes. IRD can remit penalties and interest where the delay was caused by an event beyond your control, or as part of an instalment arrangement, and it can cancel a late filing penalty where you had a valid reason. It is worth asking through myIR before assuming the full amount is payable. Filing the return even when you cannot pay avoids the filing penalty entirely.
Is filing late worse than paying late?
They are separate charges and both can apply at once, but they scale very differently. The filing penalty is a flat $50 to $500. The payment penalties and interest are percentages of the tax, so on a large bill they dwarf the filing penalty — and they keep growing until you pay. File on time even if you cannot pay, then deal with the payment.
Sources
Related Calculators
IRD UOMI Interest Rates
Every published use-of-money interest rate and its effective date.
Terminal Tax Calculator
Residual income tax against instalments paid, plus the $60k safe harbour.
Tax Pooling Savings Calculator
Compare a provider quote with IRD UOMI for the same shortfall and dates.
IR3 Filing Checker
Find out whether you had to file an IR3 for the year at all.