Tax rule NZ

GST filing frequency: monthly, two-monthly or six-monthly

How often you file GST, as Inland Revenue sets it out, and the periods Bilbx's Tax Lab shows: periods of 2 months ending January, March, May, July, September and November.

The periods Tax Lab starts with

Periods of 2 months ending January, March, May, July, September and November

Checked against Inland Revenue's own pages on . This is the figure Bilbx uses.

The rule

  1. Anyone can file monthly, and you must if your sales are over $24 million in any 12-month period.

    What Inland Revenue says

    “Anyone.”

    “You must file monthly if your sales are over $24 million in any 12-month period.”

  2. You can file 2-monthly if your sales are under $24 million in any 12-month period.

    What Inland Revenue says

    “2-monthly”

    “Anyone with sales under $24 million in any 12-month period.”

  3. You can file 6-monthly if your sales are under $500,000 in any 12-month period.

    What Inland Revenue says

    “6-monthly”

    “Anyone with sales under $500,000 in any 12-month period.”

  4. With a 31 March balance date, 2-monthly filers should file for periods ending in odd months: January, March, May, July, September and November.

    What Inland Revenue says

    “If you have a 31 March balance date:”

    “2-monthly filers should file for periods ending in odd months (May, July, September, November and January, March).”

  5. With a 31 March balance date, 6-monthly filers should file for periods ending 30 September and 31 March.

    What Inland Revenue says

    “If you have a 31 March balance date:”

    “6-monthly filers should file for periods ending 30 September and 31 March.”

How Bilbx applies it

  • Tax Lab, part of Bilbx Premium, shows your GST for each filing period, and starts with periods of 2 months ending January, March, May, July, September and November.
  • In Settings you can choose monthly, every two, three or six months, or yearly, and the month a period ends in.
  • A period that crosses the end of your tax year keeps each receipt in its own year's return.

Worked examples

Bilbx's own tests run these exact cases against the website and the app.

  • 31 March 2026

    Filing:
    Every 2 months, ending Jan, Mar, May, Jul, Sep, Nov
    Tax Lab's period:
    1 February 2026 to 31 March 2026

  • 1 April 2026

    Filing:
    Every 2 months, ending Jan, Mar, May, Jul, Sep, Nov
    Tax Lab's period:
    1 April 2026 to 31 May 2026

  • 15 December 2026

    Filing:
    Every 2 months, ending Jan, Mar, May, Jul, Sep, Nov
    Tax Lab's period:
    1 December 2026 to 31 January 2027

  • 15 March 2026

    Filing:
    Every 2 months, ending Feb, Apr, Jun, Aug, Oct, Dec
    Tax Lab's period:
    1 March 2026 to 30 April 2026

  • 1 October 2026

    Filing:
    Every 6 months, ending Mar, Sep
    Tax Lab's period:
    1 October 2026 to 31 March 2027

  • 31 March 2026

    Filing:
    Monthly
    Tax Lab's period:
    1 March 2026 to 31 March 2026

Check a receipt

Enter a receipt to see what Bilbx does with it under New Zealand's rules. It is worked out in your browser by the same code the app runs, and nothing you enter is sent or stored.

Enter a date and a total to see the answers.

Sources

Spotted something that doesn't match Inland Revenue's guidance?

Every sentence in the rule is checked against Inland Revenue's own guidance, quoted beneath it and linked above. Last checked . Rules version 60f9162250af. Terms.

More for New Zealand: every tax rule Bilbx applies and guides on receipts and tax records.