David Musgrave provides scripts for Changing SOP Tax Rates using the Support Debugging Tool using upcoming changes to New Zealand’s tax rates.
Changing SOP Tax Rates using the Support Debugging Tool in Dynamics GP
Sales, Purchasing & InventoryInstall, Upgrade & Admin
Archived post from 2010. Dynamics GP and the links it points to have changed since; check current documentation before relying on version-specific steps.