The one-line version
POPIA says: only collect the personal information you genuinely need, use it for the reason you collected it, keep it safe, and respect people's rights over it.
Who it applies to
Almost every business that keeps customer, staff or supplier details — which is all of them. Size doesn't exempt you; a spreadsheet of clients already counts.
Size doesn't exempt you — a single spreadsheet of clients already counts.
What 'personal information' means
Anything that identifies a person: name, phone, email, ID number, address, even a photo or a customer's order history. If it points to a person, it's covered.