New Zealand tax due dates: GST, income tax, and provisional tax

New Zealand’s tax calendar looks simple from a distance: GST on the 28th, income tax in July, terminal tax in February. The complications hide in the exceptions, the provisional tax overlay, and the way several obligations land on the same handful of days (15 January and 7 May do a lot of work). Here is the full picture for a typical NZ small business with the standard 31 March balance date, verified against Inland Revenue sources in the Sources section.

GST: the 28th, with two exceptions

GST returns and payments share a single due date: the 28th of the month after your taxable period ends ^[1] . Inland Revenue carves out two exceptions ^[1] :

On a two-monthly cycle with a March balance date, that produces due dates of 28 June, 28 August, 28 October, 15 January, 28 February, and 7 May. Six-monthly and monthly filers follow the same 28th rule with the same two exceptions.

Income tax: IR3, terminal tax, and the agent extension

The extension of time regime is one of the strongest arguments for using an agent in New Zealand: filing moves from 7 July to as late as 31 March, and the terminal tax date shifts from 7 February to 7 April ^[3] . Inland Revenue cannot extend beyond 31 March; clients who genuinely cannot file by then need deferred status on application ^[3] .

Provisional tax

Once residual income tax passes the threshold, the year’s tax is prepaid in instalments. Under the standard or estimation option with a 31 March balance date, three instalments fall due ^[4] :

1. 28 August
2. 15 January
3. 7 May

Businesses on the ratio option (which ties provisional tax to GST taxable supplies) instead pay six smaller instalments: 28 June, 28 August, 28 October, 15 January, 28 February, and 7 May ^[4] . Note how 15 January and 7 May double up with GST due dates; cash-flow planning around those two days is where NZ bookkeepers earn their keep, since a GST payment, a provisional instalment, and (in May) the prior year’s loose ends can all land at once.

Employers: payday filing and PAYE payments

Filing and paying are decoupled ^[5] :

• File employment information within 2 working days of each payday.
• Pay deductions monthly by the 20th of the following month if gross annual PAYE and ESCT is under $500,000.
• Above $500,000, pay twice a month: paydays from the 1st to the 15th are due by the 20th of that month; paydays from the 16th to month end are due by the 5th of the following month.

If a date is missed

Inland Revenue charges late filing penalties on returns and late payment penalties plus use-of-money interest on unpaid tax, and the provisional tax rules add their own interest exposure when instalments fall short of the eventual liability. The pragmatic NZ-specific cushions: the agent extension of time regime moves the worst deadline (7 July) out by up to nine months for clients of an agent ^[3] , and Inland Revenue will set up instalment arrangements for taxpayers who get in touch before the debt sours. The two stacked days, 15 January and 7 May, deserve calendar warnings weeks ahead, because a GST payment and a provisional instalment landing together is a cash-flow event, not just a filing event.

Making the dates routine

Each due date above consumes the same input: a ledger that reflects what the business actually spent and earned, with the paperwork to prove it. The GST return due on the 28th is only quick if the period’s receipts and supplier bills are already coded with the right GST treatment. That capture-and-code layer is what ExpenseFlow automates: documents come in by photo, email, or drive pick-up, get extracted and coded, and sync into the accounting platform with the source attached, so the 28th, the 15th of January, and the 7th of May start from books that are already current. Filing remains in the accounting software or with the agent; ExpenseFlow keeps the inputs ready.