Provisional tax calculator NZ
Estimate New Zealand provisional tax instalments for the 2026/27 tax year using the standard uplift, prior year uplift, or estimation method.
Built for self employed people, contractors, landlords, companies, and anyone with residual income tax above the IRD threshold. Shows three instalment amounts and March balance date due dates.
What is provisional tax in New Zealand?
Provisional tax is not a separate tax from income tax. It is how Inland Revenue (IRD) lets you pay residual income tax in instalments during the year instead of one lump sum after year end. This NZ provisional tax calculator is for New Zealand only. It is not an Australian provisional tax tool and not a SARS South Africa calculator.
You generally pay provisional tax if residual income tax (RIT) from your last return was more than $5,000. That often covers self employed income, contractors, rental income, partnerships, overseas income, and companies with RIT above the threshold. Cash wages already taxed through PAYE sit in the PAYE calculator. GST on sales is separate: use the GST calculator. How GST periods and provisional tax line up is covered in GST provisional tax.
Three steps to estimate provisional tax
Choose a method
Use standard uplift at 105% of last year's RIT, prior year uplift at 110% of the year before last when the latest return is not yet filed for early instalments, or estimation when income has changed.
Enter residual income tax
Find RIT on your income tax assessment in myIR. For estimation, enter your best estimate of this year's residual tax liability.
Read the instalment schedule
The tool splits the total into three equal payments for a standard March balance date: 28 August 2026, 15 January 2027, and 7 May 2027. Confirm dates on IRD payment dates or our GST tax due date calendar.
How Kiwis and NZ companies estimate instalments
Simple examples for 2026/27. Real returns can mix filing timing, GST frequency, and AIM or ratio options.
Designer on standard uplift
Prior year RIT $12,000. At 105%, provisional tax is $12,600. Three instalments of $4,200 due 28 August, 15 January, and 7 May.
Uplift: 105%
Total: $12,600
Per instalment: $4,200
Prior year 110% uplift
Latest return not filed before early instalments. RIT from two years ago $18,000. At 110%, total provisional tax is $19,800 ($6,600 each) until the return is filed and later instalments move to last year plus 5%. Official working is on IRD standard option.
Uplift: 110%
Total: $19,800
Per instalment (simplified): $6,600
Company provisional tax calculator example
A close company with RIT $40,000 uses standard uplift: $42,000 for the year, $14,000 per instalment. Companies use the same RIT and uplift framework as individuals. Confirm company dates and method in myIR.
Uplift: 105%
Total: $42,000
Per instalment: $14,000
Under the $5,000 threshold
RIT $3,200. Generally no provisional tax instalments. You usually pay as terminal tax after the year. This is the $5,000 threshold, not the separate under $60,000 UOMI interest timing rule.
Threshold: more than $5,000
Provisional instalments: usually none
Self employed tax overview: self-employed tax calculator. Schedular payments: withholding tax calculator. Late GST filing risk: late GST penalty calculator.
Provisional tax options explained
IRD options include standard, estimation, ratio, and AIM. This IRD provisional tax calculator models the three most common amount methods for a March balance date.
Standard uplift (105%)
Default for many people. Previous year's RIT plus 5%, then divide by three (or by two if you file six monthly GST). Detail: IRD standard option.
Prior year uplift (110%)
When early instalments use RIT from two years ago because the latest return is not yet filed, IRD uses that older RIT plus 10%. Later instalments move to last year plus 5% once the return is in. This is not the same as "tax agent equals 110%".
Estimation
Estimate current year residual tax and pay that amount. Useful when income falls. If the estimate is too low, use of money interest can apply from instalment dates. Revise in myIR if income rises.
AIM and ratio
AIM aligns provisional tax with GST using approved software. Ratio uses GST taxable supplies. Both need IRD registration and compatible processes. This tool does not replace AIM software or ratio worksheets.
Provisional tax reference 2026/27
Rules for a standard 31 March balance date. Non standard balance dates differ. Confirm in myIR.
| Item | Details |
|---|---|
| Provisional tax threshold | RIT more than $5,000 from your last return |
| Standard uplift | 105% of prior year RIT (RIT plus 5%) |
| Older RIT uplift | 110% of RIT from two years ago when that figure is used for early instalments |
| UOMI underpayment | 8.97% a year from 16 January 2026 (confirm current rate on IRD) |
| Interest timing under $60,000 RIT | On the standard option, interest generally from the day after end of year tax due date if RIT is under $60,000. See IRD interest on provisional tax. |
| Terminal tax (typical) | 7 February, or 7 April if you have a tax agent with an extension of time |
Three instalment schedule (standard / estimation)
| Instalment | Period covered | Payment due |
|---|---|---|
| Instalment 1 | 1 April to 31 July 2026 | 28 August 2026 |
| Instalment 2 | 1 August to 30 November 2026 | 15 January 2027 |
| Instalment 3 | 1 December 2026 to 31 March 2027 | 7 May 2027 |
Two instalments (six monthly GST)
If you file six monthly GST returns, provisional tax is usually two equal instalments: 28 October and 7 May for a March balance date.
| Instalment | Period covered | Payment due |
|---|---|---|
| Instalment 1 | 1 April to 30 September 2026 | 28 October 2026 |
| Instalment 2 | 1 October 2026 to 31 March 2027 | 7 May 2027 |
Older year searches (2016 to 2025) still use the same uplift ideas, but thresholds, interest rates, and due date calendars change. Always use the current IRD year. For GST late payment interest and penalties, use the late GST penalty calculator.
Use of money interest and the $60,000 rule
Use of money interest (UOMI) is a charge for having the use of money, not a separate tax. From 16 January 2026 the underpayment rate used across IRD interest pages for that period is 8.97% a year. Confirm the live rate before you budget. IRD does not charge or pay interest if the under or over amount is $100 or less.
On the standard option, if residual income tax is under $60,000, interest generally starts from the day after the end of year tax due date when you have paid required amounts on time. If RIT is $60,000 or more, interest timing is different and can run from after the final instalment. On estimation, shortfalls can attract interest from each instalment date even if you paid your estimated amounts on time. Official detail: IRD interest on provisional tax.
Do not confuse the $5,000 entry threshold with the under $60,000 interest timing rule. Both matter. This page's banner only flags the $5,000 threshold.
Terminal tax
After you file, IRD compares residual income tax with provisional tax paid. The difference is terminal tax (to pay or refund). Typical due dates are 7 February, or 7 April with a tax agent extension. If you were under the $5,000 threshold, your full RIT is usually paid as terminal tax by that date.
Employer fringe benefits are a different tax. Use the FBT calculator. Invoices for trading: GST invoice generator.
First year and new provisional tax liability
In a first year of self employment there is often no prior RIT, so you may not pay provisional tax during that year. You still owe income tax at year end. From the next year, if RIT is more than $5,000, provisional tax usually starts. New operators can follow the new business GST compliance roadmap.
IRD also describes limited cases where you must pay provisional tax in a current year even without a prior provisional history, for example certain individuals moving from employment into untaxed activity with high current year RIT, and some non individuals starting a taxable activity. Read those rules on the interest page above before assuming you are exempt. Registration for GST when you grow: register for GST in NZ. Contractor vs employee: contractors vs employees.
How to pay provisional tax
Check myIR
Confirm method and amounts under Income Tax registration details in myIR.
Pay online
Use your bank's Pay Tax / Pay IRD function. Tax type INC covers income tax and provisional tax. Enter your IRD number and pay before the due date.
Revise estimates
If income changes, update your provisional tax estimate in myIR so remaining instalments match your forecast.
Four provisional tax mistakes
1. Treating $5,000 as a soft limit
RIT of more than $5,000 triggers provisional tax. There is no rounding grace. Check the assessment figure, not a rough mental estimate.
Common for side rental and investment income2. Underestimating on the estimation method
A low estimate can attract UOMI from instalment dates. Revise upward in myIR if income recovers.
High risk for variable contractors3. Mixing up 105% and 110%
105% is last year RIT plus 5%. 110% is for older RIT from two years ago when that figure drives early instalments. Using the wrong base year produces the wrong amount.
Common when returns are filed late4. Assuming only sole traders pay
Companies, landlords, investors, and employees with large untaxed amounts can all face provisional tax when RIT exceeds $5,000.
Catches first time property investorsOur verification process
How rules are checked against IRD sources.
Provisional tax figures on GSTCalc.nz are checked against published IRD guidance before they go live:
IRD cross-check
Threshold, uplifts, instalment dates, and interest timing are verified against IRD provisional tax pages.
Worked examples
Scenario maths use the same engine as the live calculator.
Honest limits
This tool estimates equal three instalment cases. Mid year filing switches, AIM, ratio, and non March balance dates need myIR or an adviser.
What we are: A free provisional income tax calculator aimed at IRD published rules for budgeting. Ads may help fund the site. We are not Inland Revenue and this is not tax advice.
What we are not: A substitute for professional advice. For trusts, groups, or non standard balance dates, talk to a tax agent or contact IRD. Publisher: About us and Contact. Privacy: Privacy policy.
Provisional tax FAQs
Provisional Tax Breakdown
Instalment schedule · New Zealand · GSTCalc.nz
This report was generated by gstcalc.nz. Free NZ provisional tax calculator. Rules checked against IRD published guidance.
Calculations use IRD 2026/27 provisional tax uplift rules for equal three instalment estimates. Confirm your method and dates in myIR.
Disclaimer: This document is for informational and budgeting purposes only. It does not constitute financial or tax advice.
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