NZ PAYE Square-Up Calculator
This calculator works out whether you are due a tax refund or you owe IRD money once your PAYE year ends on 31 March, mirroring the automatic square-up IRD runs against your actual income. PAYE assumes you earn at the same rate all year, so anyone with multiple jobs, a mid-year pay change, a bonus, or investment income can end up over or under-taxed without knowing it. You enter your total salary and wage income from every employer for the year, other taxable income such as interest, dividends, rent or self-employed earnings, total PAYE (including ACC earners' levy) deducted from your payslips, other tax credits such as RWT or imputation credits, whether you qualified for the independent earner tax credit, and your student loan status and repayments withheld. The calculator returns your outcome as a refund, a bill, a small amount written off under $200, or square, alongside an income tax breakdown showing taxable income, income tax, ACC levy, credits and residual income tax (RIT), plus a student loan reconciliation where relevant. It also flags whether your RIT tips you into provisional tax next year, or whether non-wage income means you must file an IR3. Run it once you have your final payslip so you can plan ahead. This is an estimate only; IRD's actual calculation uses payroll data from payday filing, and small rounding differences may occur.
Annual income
Tax already withheld
Tax code & status
How the square-up works
PAYE is calculated by your employer assuming you will earn at your current pay rate for a full 52-week year. This gives a good approximation when you work full-year at one employer. But the system breaks down in these cases:
- Partial-year work: If you worked only 6 months of the year, you may have been taxed in a higher bracket than your actual total annual income requires.
- Multiple jobs: Each employer only sees the income they pay you. The secondary tax code approximates your combined bracket but isn't exact, especially if your total income crosses into a higher bracket.
- One-off bonuses: A large bonus can push PAYE into a higher bracket for that pay period, over-withholding if your annual income stays below that bracket.
- Investment income: Interest has RWT deducted at your chosen rate, which may not match your marginal rate. Dividends carry imputation credits that adjust the tax.
Residual Income Tax (RIT) and provisional tax
Your RIT is the balance of tax owed after all withholdings and credits. The key thresholds:
- RIT ≤ $200: Written off automatically for most wage earners (no action needed).
- $200 < RIT ≤ $5,000: Pay the balance by 7 February (or 7 April via tax agent).
- RIT > $5,000: You become a provisional taxpayer for next year. Pay your RIT by 7 Feb/7 April, plus three instalments of next year's provisional tax.
Do I need to file an IR3?
You must file an IR3 if you have any income that wasn't fully taxed at source:
- Self-employment / sole trader income
- Rental property income (or loss)
- Overseas income (offshore dividends, foreign pensions, FIF)
- Bright-line property sale proceeds
- Shareholder salary from a close company
- Income from a partnership
- Schedular payments (WT deducted)
If you have only PAYE wage income (even from multiple jobs), you don't need to file. IRD will auto-calculate your square-up and notify you.
Sources
This tool provides an estimate only. IRD's auto-calculation will use actual payroll data submitted via payday filing. Small timing differences and rounding may produce minor variations.