How it works on Yaff
Yaff does not add GST or VAT at checkout, does not file returns, and has no Stripe Tax integration. Terms put tax on the seller. Whether you charge tax inclusive or extra is between you, your tax authority and an accountant. New Zealand GST is administered by IRD; Australia has GST rules via the ATO; VAT applies in the UK, EU and elsewhere.
Example
A GST-registered creator in New Zealand might set membership prices GST-inclusive and account for the tax in their own return. A VAT-registered creator would do the equivalent with their local authority.