Only registered vendors charge VAT
You may add VAT to an invoice only if your business is registered for VAT with SARS. Charging VAT when you are not registered is an offence, so if you are not registered, your price is simply your price.
Registration becomes compulsory once your taxable supplies pass R2.3 million in any 12 months. SARS raised that threshold from R1 million with effect from 1 April 2026. Below it, you can still choose to register voluntarily if you meet SARS's conditions.
Not everything is 15%
Some supplies are zero-rated (VAT at 0%, for example certain basic foodstuffs and exported goods), and some are exempt (no VAT at all, for example certain financial services and residential rent). If you sell any of those, a flat 15% is wrong for those lines. When in doubt, check with SARS or your accountant.
Rounding to the cent
Work VAT out on the line or on the total, round to the cent, and make the three figures — excluding VAT, VAT and including VAT — add up exactly. This calculator takes the VAT out of an inclusive price and then works the excluding figure as the difference, so the parts always add up to what you typed.