The home office deduction is one of the most consistently under-claimed tax deductions for self-employed writers in New Zealand. Either writers don't know it exists, think it's too complicated to calculate, or assume it won't amount to much. In practice, it can reduce your taxable income by several thousand dollars a year — which, at a 30% tax rate, is real money back in your writing business.
Here is how it works, how to calculate it, and what you need to keep track of.
Who can claim it
You can claim a home office deduction if you are self-employed (which includes freelance writers, sole traders, and contractors) and you use a dedicated space in your home for business purposes on a regular basis.
"Dedicated space" doesn't mean you need a separate room — though that makes the calculation cleaner. It means a space that is used primarily for work. A study that's used for your writing during the day and nothing else is clearly a dedicated space. The corner of a shared living room where you sometimes work is harder to justify.
The stronger your case that the space is used for work rather than personal purposes, the cleaner your deduction. A room with a desk, bookshelves, and your manuscript in it is a much clearer home office than a kitchen table.
Two methods — IRD's square metre rate and actual costs
IRD offers two ways to calculate the deduction. Most writers will find the square metre rate method simpler.
Square metre rate method: IRD sets an annual rate per square metre of home office space. For the 2025–26 tax year, this rate is $53.10 per square metre. You measure the floor area of your home office, multiply it by the rate, and that's your deduction — no receipts required for the premises costs themselves.
Example: Your home office is 12 square metres. 12 × $53.10 = $637.20 deductible for the year from the premises rate alone. You can then also claim a proportion of your actual power and internet costs based on the percentage of your home your office represents.
Actual costs method: You calculate the total annual running costs of your home (rent or mortgage interest, rates, insurance, power, internet) and multiply by the percentage of your home's floor area that is your office. This requires more record-keeping but can produce a higher deduction if your household costs are significant.
Example: Your home is 120 square metres and your office is 12 square metres — 10% of the total. Your annual household costs are $30,000. 10% of $30,000 = $3,000 deductible.
"The home office deduction can reduce your taxable income by several thousand dollars a year. Many freelance writers miss it entirely."
What costs are included
Under the actual costs method, the household expenses you can include in the calculation are:
- Rent — the full annual rent if you're renting
- Mortgage interest — not principal repayments, only the interest component
- Rates (council rates on the property)
- Home and contents insurance (the portion relating to the building and contents)
- Power and gas
- Internet — though this may be separately claimable at a higher proportion if your internet use is primarily for work
Note: if you own your home, you cannot claim depreciation on the building itself for a home office — this was changed by IRD some years ago. Mortgage interest is claimable; depreciation is not.
What you need to keep track of
For the square metre rate method: the floor measurements of your home office and your total home floor area. You only need to measure once unless you move. You'll also want to track your actual power and internet costs separately so you can claim those on top of the rate.
For the actual costs method: your total annual costs in each category (rent, rates, insurance, power, internet), and the floor area calculation to determine your percentage. Keep copies of your power bills, rates notices, insurance certificates, and mortgage interest statements.
A simple spreadsheet updated monthly — or a dedicated section in your accounting records — is sufficient. The goal is to have clean numbers ready when your accountant asks for them in April.
A note on the 2025–26 tax year rate
The IRD updates the square metre rate annually. The figure used in this article ($53.10 per square metre) is the rate for the 2025–26 tax year (1 April 2025 to 31 March 2026). Always check ird.govt.nz for the current year's rate before calculating your deduction.
Is it worth it?
On a 12 square metre office in a mid-sized NZ home, the actual costs method might produce a deduction of $2,500 to $4,000 depending on your household costs. At a 30% tax rate, that's $750 to $1,200 in reduced tax. That is worth twenty minutes of record-keeping per month.
The writers who miss this deduction are almost always the ones who haven't set up the habit of tracking it. Set it up once, keep the numbers current, and claim it every year. It's a legitimate deduction that exists specifically to recognise that working from home has real costs — and as a freelance writer, your home is your business premises.