FBT Quarterly Return Estimator NZ 2026 (IR420)
This calculator helps you build your quarterly IR420 Fringe Benefit Tax return by pulling every benefit type into one place and working out the tax on each. Choose which quarter you're filing (Q1 to Q4) and your FBT rate, either the single rate of 63.93% or the alternate rate of 49.25% for quarters one to three, then enter the fringe benefits your business provided. Add each company vehicle available for private use, its value, calculation method (cost price or tax book value), the days available up to 90, and any employee contribution; enter low-interest loans with their average balance and prescribed versus actual interest; total your quarterly insurance and superannuation contributions; and record unclassified benefits such as gifts and vouchers, flagging whether the de minimis exemption applies. The calculator returns the taxable value for each IR420 box (A, D, E and B), the combined Box 3 total, the FBT rate applied, and the Box 5 amount payable for the quarter, along with a reminder if a Q4 wash-up is required because you used the alternate rate earlier in the year. Use it to prepare your return before filing through myIR. Figures are an estimate only; they don't include the separate GST adjustment on benefits with GST in their cost, so check your final return against ird.govt.nz or a tax adviser.
Quarter and rate
Box A: Motor vehicles
Add each company vehicle available for private use this quarter.
| Vehicle | Method | Value ($) | Days (max 90) | Contribution ($) | Taxable value | |
|---|---|---|---|---|---|---|
| $0.00 |
Box D: Low-interest loans
| Loan / employee | Average balance ($) | Prescribed (% pa) | Actual (% pa) | Taxable value |
|---|---|---|---|---|
| $0.00 |
Box E: Insurance and superannuation
Employer contributions to medical insurance, life insurance, accident insurance, and superannuation schemes not subject to ESCT.
Box B: Unclassified benefits and other
Gifts, vouchers, gym memberships, etc. Subject to the de minimis exemption ($300/employee/quarter, $22,500/employer rolling 4 quarters).
How the IR420 quarterly return works
Every NZ employer registered for FBT must file an IR420 quarterly return covering the three months ending June, September, December, or March. The return aggregates the taxable value of all fringe benefits provided during the quarter across five boxes (motor vehicles, goods/services, subsidised transport, low-interest loans, and insurance/superannuation). The total taxable value is multiplied by the chosen FBT rate to produce the FBT payable for the quarter. The Q4 return (1 January to 31 March) is due 31 May rather than 20 April because it includes the annual wash-up calculation if the alternate rate option was used.
FBT quarter due dates
| Quarter | Period | Due date |
|---|---|---|
| Q1 | 1 April to 30 June | 20 July |
| Q2 | 1 July to 30 September | 20 October |
| Q3 | 1 October to 31 December | 20 January |
| Q4 | 1 January to 31 March | 31 May (wash-up) |
Filing options
- Quarterly (default). All employers default to quarterly filing using the IR420.
- Annual. If your gross PAYE and ESCT for the previous year were $1 million or less, you can elect to file an annual IR422 return covering 1 April to 31 March, due 31 May.
- Income year (close companies). Close companies can file an income year IR421 return aligned with their accounting year, due on the same date as the company income tax return. Available where the only fringe benefits are 1-2 motor vehicles for shareholder-employees.
FBT rate selection per quarter
You can choose the single rate (63.93%) or alternate rate (49.25%) independently for each of the first three quarters. The alternate rate only applies to quarters 1 to 3 - there is no separate alternate rate for Q4. If you use the alternate rate in any of Q1-Q3, you must perform a wash-up in Q4 using the full alternate, short-form alternate, or pooled alternate rate calculation. If you use the single rate in all four quarters, no wash-up is needed but you may apply within two months of your Q4 assessment to switch to an alternate rate calculation if it would save FBT.
Common Q1 prep checklist
- Identify every employee with a company vehicle available for private use, even if not used (FBT applies on availability)
- Calculate days available per quarter, capped at 90 days
- Reduce days for vehicle in workshop >24h, employee away on business >24h, vehicle used for emergency call
- Check the current prescribed interest rate (changes quarterly)
- Sum employer-paid medical insurance, life insurance, accident insurance premiums
- List unclassified benefits provided to each employee (gifts, vouchers, club subscriptions)
- Apply de minimis exemption ($300/employee/quarter, $22,500 rolling 4 quarters)
- Add any FBT-exempt benefits to your records (don't include in IR420)
Sources
- IRD - FBT filing returns
- IRD - Work out taxable value and file FBT return
- IR409 Fringe Benefit Tax Guide (PDF)
This calculator provides an estimate only. Always verify your FBT return with a tax adviser or refer to ird.govt.nz. The IR420 also requires a GST adjustment which depends on whether the underlying benefit had GST claimable; this calculator does not compute the GST adjustment separately.
Related calculators
- NZ FBT Calculator - calculate FBT on individual benefits
- FBT Attribution Calculator - Q4 wash-up calculation
- FBT De Minimis Calculator - check unclassified benefit thresholds
- Close Company Vehicle Calculator - should you opt out of FBT?
- Shareholder Loan FBT Calculator - FBT vs charging interest