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Planned system outage | Our online services (including myIR and submitting information using software providers) will be unavailable from 6am Saturday 14 to around 6pm Sunday 15 March while we complete some system upgrades. Planned system outage in March 2026

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 2025 to 31 March 2026
Last updated: 01 Apr 2025
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