When Is the GST Return Due in New Zealand?

For most standard GST taxable periods, the return and payment are due on the 28th day of the month following the end of the taxable period. Different dates apply to certain periods.

For the October deadline, Inland Revenue identifies 28 October 2026 as the due date for GST returns and payments for the taxable period ending 30 September 2026.

Your filing frequency may be monthly, two-monthly or six-monthly, depending on your registration and circumstances. Check your myIR account and Inland Revenue guidance to confirm your deadline.

Official source: Inland Revenue — Filing GST .

Who Needs to File a GST Return?

Businesses and other entities registered for GST generally need to file returns according to their registered taxable periods.

This may include:

• Sole traders and self-employed people registered for GST.
• Companies registered for GST.
• Contractors and service-based businesses registered for GST.
• Retailers and other businesses making taxable supplies.
• Other GST-registered organisations conducting taxable activities.

GST-registered businesses generally need to file a return for each taxable period, even when there is no GST to pay. Confirm your own obligations with Inland Revenue or a qualified tax professional.

What Should You Prepare Before Filing Your GST Return?

Preparing your records in advance can make GST filing easier and help reduce errors. Use the following checklist to review your records before submitting your return.

1. Review Your Sales and Income

Check that sales invoices and other taxable income have been recorded correctly for the relevant period. Ensure the figures in your accounting software agree with your underlying records.

2. Check Business Expenses and Purchases

Review purchase invoices and receipts. Confirm that GST claimed as an input tax deduction is eligible and supported by the required records. Not every business expense automatically qualifies for a GST deduction.

3. Reconcile Your Bank Transactions

Compare your accounting records with bank statements and payment records. Investigate missing transactions, duplicate entries and unexplained differences before submitting your GST return.

4. Review GST Collected and Claimed

Check the GST included in your sales and purchases and confirm that the appropriate GST treatment has been applied. Pay particular attention to unusual transactions, asset purchases, credit notes and transactions that may have special GST rules.

5. Check Your Cash Flow

If a GST payment is due, review whether your business has sufficient funds available. Planning ahead can help reduce last-minute financial pressure and identify when professional guidance may be useful.

What Happens If You Miss the GST Deadline?

Missing a GST filing or payment deadline can have financial consequences. Depending on your circumstances, Inland Revenue may charge late-filing penalties, late-payment penalties or interest on overdue tax.

If you are concerned that you cannot pay your GST on time, do not ignore the issue. Review your position promptly and contact Inland Revenue or a qualified tax professional to understand the available options.

Read more: Inland Revenue — Paying GST .

Are Provisional Tax Payments Also Due on 28 October?

Some businesses may have additional tax obligations around the same time. Inland Revenue lists provisional tax payments for certain taxpayers with a 31 March balance date who use the ratio option, as well as AIM instalments for eligible taxpayers with a March balance date, as due on 28 October 2026.

These obligations do not apply to every business. Payment dates depend on your tax position, balance date and payment method. Confirm your own requirements rather than assuming every business has the same deadline.

Official source: Inland Revenue — Provisional Tax Payment Dates .

Common GST Mistakes New Zealand Businesses Should Avoid

Common GST errors include:

• Missing sales invoices or recording transactions in the wrong period.
• Claiming GST on expenses that do not qualify.
• Entering transactions twice.
• Failing to reconcile accounting records with bank statements.
• Using the wrong GST treatment for a transaction.
• Leaving GST preparation until the filing deadline.
• Underestimating the cash required to pay GST.

A consistent bookkeeping process and regular review of your records can help reduce these risks. If your records are incomplete or you are unsure whether your calculations are correct, professional accounting support can help you identify issues before filing.

How Can an Accountant Help With GST?

An accountant can help you review your business records, understand your GST obligations and establish a more consistent approach to tax compliance.

Depending on the services agreed, support may include:

• Reviewing bookkeeping records and reconciliations.
• Assisting with GST calculations and return preparation.
• Identifying inconsistencies in accounting records.
• Helping you understand upcoming tax obligations.
• Supporting better cash-flow planning.
• Discussing a practical process for managing future deadlines.

The appropriate level of support depends on your business, its accounting systems and the complexity of its transactions.

Frequently Asked Questions About GST in New Zealand