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Working for Families in-work tax credit | The government has announced a temporary increase of $50 a week to the in-work tax credit from 1 April. Find out more: In-work tax credit increase from 1 April

The payroll calculations and business rules define the tax rates and thresholds, tax types business rules, and calculations needed for specific tax codes. They also cover the rules relating to KiwiSaver, student loans and employer superannuation contribution tax (ESCT).

Payroll calculations and business rules specifications

This document supports software development for both the gateway and file upload services and includes calculation examples.

Download and view the payroll calculations and business rule specifications for:

  • 1 Apri 2026 to 31 March 2027
Last updated: 01 Apr 2026
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