GST Apportionment Calculator

GST Apportionment Rules in New Zealand

When you purchase something that's used partly for your taxable activity and partly for private or exempt purposes, you can only claim the GST input credit for the taxable-use portion. The rules for determining how much you can claim are set out in section 20(3) of the GST Act 1985 and use what's called the "principal purpose" test.

The Principal Purpose Test

If an asset is acquired principally (more than 50%) for making taxable supplies, you can claim the full GST input credit at the time of purchase. You then make annual adjustments if the actual taxable use differs from what was intended. If the asset is acquired principally for non-taxable purposes, you cannot claim any input credit at the time of purchase, but you can make adjustments if you later use it more for taxable purposes.

The 5% and 95% Thresholds

If taxable use is 95% or more, you can claim the full input credit with no apportionment needed. If taxable use is 5% or less, you cannot claim any input credit. Between these thresholds, you apportion based on the actual percentage of taxable use. These de minimis thresholds simplify compliance for assets that are overwhelmingly used for one purpose.

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