Sole proprietor tax is an issue which raises its head when you personally run a business with a trade name and not through a company or corporation.
So, as a sole proprietor, you are Joe Black t/a Better Photo Agency, for example. That is, your business is Better Photo Agency and you are the only owner. A CC or a company does not feature in this set-up. Your letterhead typically has “Better Photo Agency” in big at the top and “Sole proprietor: J Black” in small at the bottom. No registration number is displayed, even if “Better Photo Agency” has been registered as a defensive name.
If you as an individual are registered for tax with SARS, then there is no need to register your sole proprietor business for tax as it is not a separate legal entity and cannot be registered for tax as such. You are the business and the business is you, as it were, and your business trading figures are reported to SARS as your own personal figures.