How to File a GST Return in New Zealand: Step-by-Step Guide

Filing your GST return in New Zealand is one of the most important tax obligations for small business owners. Whether you're filing monthly, two-monthly, or six-monthly, getting it right on time avoids penalties and keeps you on the right side of Inland Revenue (IR).

This guide walks through exactly how to file your GST return using myIR — New Zealand's online tax portal — plus when accounting software makes the whole process effortless.

Who Needs to File a GST Return?

You must register for GST if your taxable turnover exceeds NZD $60,000 in a 12-month period. Once registered, you'll file returns based on your chosen filing frequency:

• Monthly — recommended for businesses with turnover over $500K or regular GST refunds
• Two-monthly — the most common option for most small businesses
• Six-monthly — available for businesses with turnover under $500K

What You'll Need Before Filing

Before you log into myIR, gather:

1. GST-exclusive income (sales minus GST)
2. GST collected (15% of GST-inclusive sales)
3. GST paid on expenses (GST on your business purchases)
4. Bank account details if you're expecting a refund

Step-by-Step: Filing via myIR

Step 1: Log into myIR

Go to ird.govt.nz and log into your myIR account. If you haven't set one up, you'll need your IRD number and a RealMe login.

Step 2: Navigate to GST

From your myIR dashboard, select "GST" under your business profile. You'll see any outstanding returns listed here.

Step 3: Start the Return

Click "File return" next to the period you're filing for. myIR will pre-fill some information from previous returns.

Step 4: Enter Your Sales (Box 5)

Enter your total sales and income (GST-inclusive amount). This includes all invoice amounts, cash sales, and any other taxable supplies.

Step 5: Enter GST on Sales (Box 6)

Enter the GST portion of your sales. This is 3/23 of your GST-inclusive turnover (or 15% of your GST-exclusive turnover).

Example: If your GST-inclusive sales were $115,000, the GST is $15,000 ($115,000 × 3/23).

Step 6: Enter Purchases (Box 11) and GST on Purchases (Box 13)

Enter your total purchases (Box 11) and the GST you've paid on those purchases (Box 13). This is the amount you're claiming back.

Important: You can only claim GST on purchases that are for business use. Personal expenses cannot be claimed.

Step 7: Calculate and Review

myIR will automatically calculate your net GST position:

• If positive (Box 6 > Box 13): You owe GST to IR
• If negative (Box 13 > Box 6): IR owes you a refund

Step 8: Submit and Pay

Review the summary carefully, then submit. If you owe GST, pay by the due date to avoid late payment penalties via direct debit, credit card, or online banking.

GST Return Due Dates

| Filing frequency | Due date | |----------------|----------| | Monthly | 28th of following month | | Two-monthly | 28th of following month | | Six-monthly | 28th of following month |

If the 28th falls on a weekend or public holiday, the due date extends to the next working day.

Common GST Mistakes to Avoid

1. Claiming GST on non-deductible expenses You can't claim GST on entertainment expenses (50% rule), private use of assets, or personal items.

2. Missing adjustment for private use If you use a vehicle or asset partly for private purposes, you must apportion the GST.

3. Not keeping tax invoices For purchases over $50 (GST-inclusive), you need a valid tax invoice to claim GST. Over $1,000, the invoice must include the supplier's IRD number.

4. Errors in the GST period Report all sales and purchases within the correct GST period — not when you get paid or pay bills (unless you're on a payments basis).

Cash vs Invoice Basis

Invoice basis (most common): You report GST when you issue or receive an invoice, regardless of when payment is made.

Payments basis: You report GST when you receive or make payment. Available only if your annual turnover is under $2 million.

When to Use Accounting Software

Filing manually through myIR works for small operations with few transactions. As your business grows, accounting software makes GST filing dramatically easier:

• Automatic GST calculations on every transaction
• One-click return preparation — all boxes pre-filled from your real data
• GST tracking by period — see your liability in real time
• Audit trail — every transaction is linked to its GST return

Many NZ small business owners spend 3–6 hours on each GST return manually. With good accounting software, it's typically under 20 minutes.

Start a free trial of Finsori — the accounting software built for NZ small businesses.

Frequently Asked Questions

What happens if I file my GST return late? IR charges a late filing penalty of $50 for returns filed after the due date. Consistent late filing may result in a different filing frequency being imposed.

Can I amend a GST return after filing? Yes. You can file an amended return through myIR. For errors under $1,000 (GST), you can adjust in your next return.

What is the threshold for requiring a tax invoice? For any purchase over $50 (GST-inclusive), you need a valid tax invoice. Over $1,000, the invoice must include the supplier's name, address, and IRD number.

Do I need to file a nil return if I have no activity? Yes. Even with no taxable sales or purchases, you must still file a nil return to avoid late filing penalties.

What is the GST rate in New Zealand? The GST rate in New Zealand is 15%. It applies to most goods and services sold in NZ, with certain zero-rated and exempt supplies.

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Also see: NZ Invoicing Requirements 2024 · NZ Company Tax Return Guide