Or one of your client's get VAT audited and SARS wants to verify their VAT input claims and starts sniffing around verifying supplier invoices. It happens all the time. People don't understand how vast and powerful SARS' auditing powers are. When they start auditing a company they can cast their net far and wide to anyone who has dealings with the company they're auditing - clients, suppliers, shareholders, directors, senior management. An audit that starts off with one company can easily expand into a multiple-entity audit across all tax types. And the burden of proof is on the taxpayer, generally SARS doesn't have to prove a thing. They can raise an assessment and it's up to you to prove otherwise.