Small things Singapore service businesses need often enough to be annoying. No sign-up, no email, nothing stored.
Add GST to a price, or work out the GST already inside a GST-inclusive total, at Singapore's 9 per cent.
OpenWhat IRAS asks a tax invoice to show, for a full tax invoice and for a simplified one up to S$1,000. Tick them off against a real invoice.
OpenGeneral information only. Not tax advice, and it does not account for your circumstances - check anything that matters with your accountant or IRAS.