NZ GST late payment calculator

General information only, not tax advice. This is an indicative estimate of standard GST late-payment penalties (1% the day after the due date, plus a further 4% if unpaid after 7 days) and use-of-money interest (accruing daily). Your actual position can differ. Always check current rates and your own situation at ird.govt.nz or with your accountant.

How NZ GST late-payment penalties work

If you don't pay your GST return by the due date, IRD charges a 1% initial penalty the day after the due date. If the amount is still unpaid after 7 days, a further 4% incremental penalty applies.

On top of the fixed penalties, use-of-money interest (UOMI) accrues daily on the unpaid tax. The underpaid rate was 8.97% per year as at 16 January 2026. Check the current rate at ird.govt.nz before relying on it.

If you can't pay on time, contact IRD first

Contacting IRD beforeyour due date to arrange an instalment plan generally stops further penalties from accruing. If this is your first late payment in a 2-year period, IRD may also give a one-off grace period before applying penalties, but it's not guaranteed.

The worst outcome is ignoring it. The 1% + 4% structure compounds quickly on large GST balances, and UOMI adds up daily. Early communication with IRD is almost always the better path.

Where these numbers come from

The penalty structure (1% / 4%) and UOMI are set in the Tax Administration Act 1994. See IRD: Late payment penalties and the current UOMI rates for authoritative figures. This calculator is a generic illustration, not a substitute for checking your actual notice from IRD.