GST Mixed-Use Asset Calculator NZ 2026

This calculator works out how much GST input tax you can claim on a holiday home, bach, boat or aircraft that you both rent out for income and use privately during the year. Because a straight 100% GST claim is not allowed on a mixed-use asset, you can only claim the income-earning share, alongside separate income tax rules running in parallel. You enter the asset type, its GST-inclusive cost (or market value), the days it earned income at market rates, the days it was used privately, the days it sat unused, your gross rental income, your mixed expenses covering both uses, and any expenses relating only to income-earning use. The calculator returns the total days used, your income-earning use percentage, the GST hidden inside your mixed expenses, the apportioned claim on those expenses, the full claim on pure income-earning expenses, and your total GST input tax claim. It also flags whether your boat or aircraft meets the $50,000 mixed-use threshold, whether the asset passes the 62-day unused test, and whether your rental income is low enough to opt out of the mixed-use rules altogether. Use it to sanity-check a GST return or to weigh up whether opting out saves more in compliance hassle than it costs in forgone claims. This is a planning tool only, so confirm your figures and eligibility with an accountant or IRD before filing.

Updated  Reflects the 1 April 2024 simplification: section 20G method is no longer mandatory but remains an acceptable fair and reasonable method.
Calculate.co.nz recommends jobtracker.co.nz, a New Zealand job hunt and career tracker built by the same team. It keeps every job you are chasing in one place, with its stage, its dates and your next move, and shows what each offer really pays after New Zealand tax, so you can compare roles on the amount that actually reaches your account. Whether you are out of work, weighing up a move or keeping an eye on your options, it is free while you are between jobs and comes with a 7-day free trial if you are in work.
jobtracker.co.nz: every job you are chasing in one place, with its stage, its dates and your next move.
Advertise on this page

Asset details

$

Annual usage (days)

days
days
Includes use by associated persons (family, friends paying mates' rates) and any use by anyone paying less than 80% of market rate.
days
Days the asset was sitting empty. Excluded from the apportionment formula. Total of all three should equal 365.

Income earned

$

Mixed expenses (relate to BOTH uses)

$
Rates, insurance, building maintenance, depreciation, utilities. Excludes purely income-earning expenses (advertising, cleaning fees) and purely private expenses.
$
Advertising, booking platform fees, cleaning between guests, linen hire. These give a full GST credit regardless of usage split.

The mixed-use asset rules in 2026

From 1 April 2024, IRD simplified the GST treatment of mixed-use assets. The special section 20G calculation is no longer mandatory. Owners can use the general GST apportionment rules instead, OR continue with the old section 20G formula as a "fair and reasonable" method. Both produce similar results in most cases. The income tax mixed-use asset rules still apply separately.

The apportionment formula

Income-earning use percentage = income-earning days ÷ (income-earning days + private days). Days the asset is unused (vacant) are excluded entirely - they neither help nor hurt your GST claim.

This percentage is applied to mixed expenses (rates, insurance, building maintenance, depreciation - things that relate to both income and private use). Pure income-only expenses (advertising, cleaning between guests) are 100% claimable. Pure private expenses are 0% claimable.

The $50,000 threshold for boats and aircraft

Boats and aircraft only fall under the mixed-use rules if they cost $50,000 or more. A $30,000 jet ski rented occasionally falls under standard apportionment rules instead. Holiday homes have no minimum threshold.

Opt-out for low income

If gross income from the income-earning use of the asset is less than $4,000 in the tax year, you can opt out of the mixed-use asset rules entirely. No income to declare, no expenses to claim, no GST adjustments. Useful for occasional Airbnb users or someone who chartered the boat once.

Sources

Related calculators

Related calculators

Frequently asked questions

What is a mixed-use asset for NZ GST purposes?

A mixed-use asset is a holiday home, bach, boat, or aircraft (boats and aircraft must cost $50,000 or more) used during a tax year both to derive income (typically short-term rental) AND for private purposes by the owner or their family. The asset must also be unused for at least 62 days in the year. From 1 April 2024, the special section 20G calculation is no longer mandatory; general GST apportionment rules apply, with the old method allowed as a fair and reasonable approach.

How is the GST claim calculated on a mixed-use holiday home?

The income-earning use percentage is calculated as: income-earning days divided by total used days (income-earning days + private days). Days the asset sits empty are excluded. This percentage is applied to mixed expenses (rates, insurance, repairs, depreciation). Expenses that relate solely to income-earning use (advertising, cleaning between guests) are 100% claimable. Expenses that relate solely to private use (no claim).

Can I opt out of the mixed-use rules?

Yes, if your gross income from the income-earning use of the asset is less than $4,000 in the tax year, you can opt out and exclude both the income and the expenses from your GST and income tax returns. This is useful for low-frequency rentals where the compliance work outweighs the benefit. Once you opt out, you cannot claim any GST on the asset's expenses for that year.

What is the $50,000 threshold for boats and aircraft?

Boats and aircraft are only mixed-use assets if they cost $50,000 or more (or had a market value of $50,000 or more if not acquired at market value). Below this threshold, the standard general apportionment rules apply. Holiday homes have no minimum threshold - any short-term rental property used privately is potentially a mixed-use asset. The $50,000 threshold is calculated on the cost to the partnership or LTC, not to individual partners.