GST Audit Risk Self-Assessment

Understanding GST Audit Risk in New Zealand

Inland Revenue uses data analytics and risk profiling to identify businesses most likely to have GST compliance issues. While the exact algorithms are not public, the risk indicators are well understood from published IRD guidance, audit case studies, and professional experience. This tool scores your business against the most commonly cited risk factors.

What Triggers an IRD GST Audit?

The most common triggers include: consistently claiming GST refunds (suggests expenses exceed sales, which is unusual for most businesses and draws scrutiny), late filing or payment history (indicates poor record-keeping), cash-based businesses (higher risk of underreported income), large or unusual one-off claims without supporting documentation, lifestyle inconsistent with declared income, and significant year-on-year swings in GST positions without clear business reasons.

How to Reduce Your Risk

The best protection is simple: keep good records, file on time, pay on time, and ensure every input credit is backed by a valid tax invoice. If you have a genuine reason for unusual GST patterns (a large capital purchase, a seasonal business, an export period), document the reason in your records so you can explain it if asked. Consider engaging a qualified accountant, even just for an annual review of your GST processes.

For the full suite of GST tools, visit the GST.co.nz homepage. For 200+ other NZ calculators, visit Calculate.co.nz.

Last updated: April 2026 | Rates current for the 2026/27 tax year