GST, invoice numbers and checkout terms
What Organisation Settings → Checkout & tax controls.
01GST
Turn on GST registered and 15% is applied to standard lines, with your GST number carried on the paperwork. Totals are frozen server-side the moment an invoice is issued, so a later rate or setting change can never rewrite an invoice you already sent.
02Invoice numbering
You choose the prefix; the server issues the numbers gap-free and shows you which one is next. It is deliberately not editable — a gap in an invoice sequence is a question you do not want to be answering later.
03Payment terms and when you collect
Set the default terms invoices carry — on receipt, or net 7, 14 or 30 days — and an optional footer note. The same panel decides when money is asked for: Pay now for bookings makes the customer authorise a one-off bank payment to confirm, while allowing pay-later for services lets you collect on completion instead.