Tax deductions

Published Thursday 23 July 2026

Table of contents

• What is a tax deduction?
• How do tax deductions work in New Zealand?
• Example of a tax deduction calculation
• What expenses can you claim?
• What you can’t claim
• Rules for claiming a deduction
• Keeping records for Inland Revenue
• Track your deductible expenses with Xero
• FAQs on tax deductions
• Related terms
• Learn more about tax deductions

Key takeaways

• A tax deduction is a business expense you subtract from your gross income, which lowers the taxable income you pay tax on.
• A deduction reduces your taxable income rather than cutting your tax bill dollar-for-dollar, so the actual saving depends on your marginal tax rate.
• You can claim costs with a genuine business purpose, and you claim only the business portion of anything used for both work and personal life.
• Keep receipts and records for at least 7 years so you can back up every claim if Inland Revenue asks.

What is a tax deduction?

A tax deduction is a business expense that can lower the amount of tax you have to pay. It’s deducted from your gross income to arrive at your taxable income. It’s sometimes called a tax write-off.

For small business owners and sole traders, tax deductions are one of the simplest ways to keep more of what you earn. Most of the everyday costs of running your business count, as long as they’re genuinely business related.

How do tax deductions work in New Zealand?

A tax deduction lowers the income you get taxed on, not your tax bill directly. So a $1,000 deduction doesn’t save you $1,000 in tax; it takes $1,000 off the income your tax is calculated on.

How much you actually save depends on your marginal tax rate, which is the rate that applies to your top slice of income. New Zealand’s top personal rate is 39% on income over $180,000, so a higher earner saves more from the same deduction than someone on a lower rate. If you’re a sole trader, your business profit is taxed as personal income, and this guide to sole trader tax walks through how that works.

Deductions also connect to GST. If you’re registered, it helps to understand how GST works before you sort your claims, because the GST side is handled separately from your income tax deductions.

Example of a tax deduction calculation

A quick example shows how deductions change the income you’re taxed on. Say Jo owns a photography studio.

Jo earned $77,000 over the year and has $15,000 of deductible business expenses. Subtracting those expenses from her gross income leaves a taxable income of $62,000, which is the figure her income tax is worked out on.

What expenses can you claim?

You can generally claim the running costs of your business, which is a practical way to keep more of your income and manage your overheads. If you’d like broader ideas, these tips for cutting business costs pair well with claiming what you’re owed.

Common deductible business expenses in New Zealand include:

• rent or lease of business premises
• power, phone and internet
• vehicle and travel for business
• a portion of home office costs
• business insurance
• depreciation on assets
• ACC levies
• professional fees, such as an accountant or lawyer
• stationery and postage
• work-related subscriptions

If a cost is part business and part personal, you claim only the business portion. And if you’re GST-registered, you claim the GST-exclusive amount, because you can claim the GST back separately through your GST return.

What you can’t claim

Some costs sit outside what counts as a business expense, so it pays to know them before you file. Claiming these can lead to problems if Inland Revenue reviews your return.

Expenses you can’t claim include:

• personal or private spending, such as groceries
• the principal portion of loan repayments
• fines and penalties, such as parking or speeding tickets, and Inland Revenue late-payment penalties
• most everyday clothing

Rules for claiming a deduction

A few simple tests decide whether an expense is deductible. Getting these right keeps your claims clean and easy to defend.

• The expense must have a genuine business purpose.
• Apportion anything used for both business and personal life, so a phone used 80% for business means you claim 80% of the cost.
• Keep proof of every expense you claim.

Keeping records for Inland Revenue

Good records are what turn a valid expense into a claim you can stand behind. They also make tax time far less stressful.

You must keep receipts and records for at least 7 years. Storing them (ideally digitally) protects you if Inland Revenue (IRD) audits you, and it’s much easier when you track your expenses as you go rather than scrambling at year end.

Track your deductible expenses with Xero

Claiming deductions gets easier when your expenses are organised throughout the year. When receipts and business costs are captured as they happen, Xero can help you spend less time on admin and less time hunting for paperwork.

Xero keeps your expenses in one place, so you can see what’s deductible and back up your claims at tax time. Start today and keep your records tidy so nothing slips through the cracks. Get one month free.

FAQs on tax deductions

Here are answers to some frequently asked questions about tax deductions for New Zealand businesses.

What’s the difference between a tax deduction and a tax credit?

A deduction lowers the income you’re taxed on, while a tax credit reduces the tax you owe directly. That makes a credit worth its full value, whereas a deduction’s value depends on your tax rate.

Can I claim expenses without a receipt?

You need evidence for the expenses you claim, so a missing receipt makes a claim hard to support. Bank or card statements can help, but a proper receipt or invoice is safest.

How much will a tax deduction save me?

Your saving equals the deduction multiplied by your marginal tax rate, not the full amount of the expense. So a $1,000 deduction saves $390 for someone on the 39% rate.

Do I need an accountant to claim deductions?

You can claim deductions yourself, and many sole traders do. An accountant can be worth it for more complex claims or to make sure you’re not missing anything.

Related terms

• Income tax
• Gross profit
• Operating profit
• Gross profit vs net profit

Learn more about tax deductions

• GST guide for business
• Small business accounting guide
• Guide to sole proprietor accounting software
• Small business accounting tips and guides