GST registered

One switch in Settings. Sole traders start with it on.
- On: quotes and invoices carry a 10% GST line, invoices print as Tax invoice, the BAS helper is available.
- Off: no GST line, documents print as Invoice, no BAS helper.
The 10% rate is fixed by law and cannot be edited. There is no per-line GST-free option.
If you are not registered for GST, keep this off. A Tax invoice from an unregistered business is a problem for your customer, not just for you.