MoneyWorks Manual
Changing the GST Parameters
You may change your GST cycle or even move from a payments to an invoice basis. The tax rates themselves might also change — see Changing Tax Rates.
Change of assessment basis: If the way you are assessed for GST changes from an invoice/accrual to a payments/cash basis (or vice versa) your next GST calculation will be handled correctly — even the partially paid invoices. All you need do is change the GST settings in the Preferences dialog box.
Change of GST Cycle: If your GST cycle changes (e.g. from 3 monthly to 1 monthly), all you need do is change the GST cycle and the GST cycle date in the Preferences dialog box. Because each transaction is stamped when processed for GST, MoneyWorks will handle this correctly.