GST registration settings

1 min readUpdated 16 Aug 2026

Your GST settings live under Organisation settings and drive how every transaction is treated and how returns are calculated. They should mirror your IRD registration exactly.

The three settings

  • GST number — your IRD-issued registration number. It appears on your tax invoices automatically.

  • Filing frequency — monthly, two-monthly, or six-monthly, matching what you registered for with IRD. This sets the periods the GST page offers you.

  • Accounting basis — payments basis (GST when money moves) or invoice basis (GST when invoices are issued). See Payments vs invoice basis explained.

Not registered?

Leave registration off and Nightbooks keeps everything GST-free — no GST on invoices, no GST split on expenses, no returns to prepare. If you later register (compulsory once turnover passes $60,000 in 12 months), switch it on and GST treatment starts from your registration date.

Changing settings later

Frequency and basis changes are registered with IRD first, then updated here to match. Nightbooks applies the change going forward; already-filed periods are untouched.

The single most common GST setup mistake is a mismatched basis — Nightbooks on invoice basis while IRD has you on payments. Check both once and this never bites you.

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