How to do a GST return in NZ: filing in myIR, box by box

A New Zealand GST return has eleven working boxes and one rate, which makes it look simpler than it is. The arithmetic is fixed: take the GST-inclusive total and multiply by three twenty-thirds. The judgement is all in what goes into the totals, and that is decided long before anyone opens myIR. This guide takes a bookkeeper through one filing run: closing the period, checking the coding, filling the boxes, testing the result, filing, and then the rules for due dates, mistakes, and penalties. What is and is not subject to GST is covered in the New Zealand GST guide. Every rule below links to Inland Revenue in the Sources section.

Before you open the return

Close the period

• Reconcile every bank and card account to the last day of the taxable period.
• Enter every sale and every purchase that belongs in the period under the client’s accounting basis.
• Clear anything uncoded. An uncoded transaction has no GST treatment.

The accounting basis matters here. On the payments basis, GST follows the money; on the invoice basis, it follows the invoice date; the hybrid basis mixes the two. The same month of transactions gives different returns under each, so confirm the software is set to the basis the client is registered on. The basis also decides the size of the late filing penalty, as covered below.

Check the coding

Run the GST detail report and look for the usual problems:

• Zero-rated against exempt. Zero-rated supplies go on the return; exempt supplies do not.
• Purchases with no GST in them: bank fees, interest, wages, residential rent, purchases from unregistered suppliers.
• Entertainment, where only half is claimable.
• Private use of vehicles, phones, and home office costs.
• Overseas suppliers, including software subscriptions.
• Imported goods. The return’s purchases box excludes them ^[1] ; GST paid at the border is dealt with separately.
• Purchases without the records required to support the claim.

The boxes

The paper return, GST101A, numbers the working boxes 5 to 15 ^[1] . myIR and accounting software ask for the same figures.

Two things follow from the layout. Box 11 should contain only purchases that include GST you can claim: put a GST-free purchase in it and Box 12 will claim three twenty-thirds of something that never had GST in it. And adjustments are kept apart, in Boxes 9 and 13, so private-use and similar corrections are visible instead of buried in the totals.

Test the result

• Box 5 against the profit and loss. Sales for the period, grossed up for GST, should agree to Box 5, or you should be able to list the differences.
• Box 11 against the ledger. Total purchases coded as including GST should agree.
• Compare with the last few returns. A ratio of purchases to sales that jumps needs a reason.
• Look at Box 15’s direction. A refund for a client who normally pays, or the reverse, should have an explanation you can give in one sentence: a large asset purchase, a seasonal dip, stock bought ahead.
• Agree to the GST account. After posting, the GST account balance should equal Box 15 plus anything unpaid from earlier periods.

Filing

In myIR

Inland Revenue’s steps ^[2] :

1. In myIR, select Returns and transactions next to the GST account.
2. Select the File return link next to the period.
3. Select whether or not you are filing a nil return.
4. Choose a filing option: GST amounts, or Total sales and purchases.
5. Fill in sales and income, purchases and expenses, and any credit and debit adjustments.
6. Review the assessment.
7. Choose how to pay, or choose to pay later.
8. Submit. You can attach correspondence or receipts first.

Before starting you need three figures: total sales and income, total purchases and expenses, and adjustments from the calculation sheet ^[2] .

From accounting software

If the client’s accounting software supports it, the return can be filed directly from the software ^[2] . This is the better route for most clients, because the figures filed are the figures in the ledger with no rekeying in between.

Acting for a client

To file for clients, a bookkeeper needs their own myIR account and typically represents clients for GST and PAYE once registered with Inland Revenue as an intermediary ^[3] . Set this up at onboarding; see the client onboarding checklist. Get the client’s approval of the figures in writing before each return goes in.

Due dates, payment, and refunds

A GST return is due by the 28th of the month after the end of the taxable period. The return for the period ending 31 March is due by 7 May, and the return for the period ending 30 November is due by 15 January. A return must be filed for every taxable period, even if it is nil ^[4] .

Payment can be made by direct debit, credit card, or debit card as part of filing in myIR. If the return shows a refund, Inland Revenue says it will pay within 15 working days ^[2] .

All dates for the year are in NZ tax deadlines.

Fixing mistakes

Inland Revenue’s rule is in two parts ^[5] . You can fix mistakes in your next return if either:

• the tax difference caused by the mistakes is $1,000 or less, or
• the tax difference is the same as or less than the lower of $10,000 or 2% of your GST output tax for the return period.

Above those limits, amend the original return. Inland Revenue says you may be able to do that in myIR, and if not, you ask it to change the return ^[5] .

A purchase that was simply never claimed is treated differently from a mistake. Inland Revenue allows previously unclaimed purchases to be claimed in a later return within two years, and beyond that in limited cases such as being unable to get the documents, a dispute over price, or a clear mistake or simple oversight ^[5] .

Whichever route you use, write down the period the error came from, the GST involved, what kind of error it was, and the return it was corrected in, and keep the note with the working papers.

Late filing

The late filing penalty for a GST return is $50 if the business is on the payments basis and $250 if it is on the invoice or hybrid basis ^[6] . The amount is fixed by the accounting basis, not by the size of the return, so a nil return filed late on the invoice basis still costs $250.

Late payment is a separate matter with its own penalties and interest. If a client cannot pay, file on time regardless: it avoids the filing penalty and keeps the amount owed certain.

After filing

• Lock the period in the ledger.
• File the working papers: the return as filed, the GST detail report, the reconciliation to the GST account, and the client’s approval. See workpapers and audit trail.
• Note anything to pick up next period.

At year end the March return gets extra attention, because it closes the GST account for the year; see the 31 March checklist.

Where ExpenseFlow fits

The coding checked before the return is set when each purchase is first captured. ExpenseFlow reads every line of a bill or receipt and assigns GST treatment using a New Zealand rule set, including the financial-services exemption. Entertainment that is only 50% claimable is split automatically into a claimable and a non-claimable line with the right tax code and account for each. It flags a missing or invalid tax code, a cross-border purchase coded as domestic, and a tax rate outside the expected range. It extracts the supplier’s GST number from the document and shows it; it does not validate the number. Each item waits in a review queue until a person approves it, then syncs to Xero or QuickBooks Online.

ExpenseFlow does not prepare or file the GST return and does not make payments to Inland Revenue.