Fair reason and fair process — you need both
The LRA recognises three fair reasons to dismiss: misconduct (the worker did something wrong), incapacity (they can't do the job, through poor performance or ill health), and operational requirements (the role falls away — retrenchment). But a fair reason alone isn't enough: you also need a fair procedure. A genuinely guilty worker dismissed without a proper process can still win an unfair-dismissal case on the procedure.
The process for misconduct
Schedule 8 expects a fair, if informal, process: look into what happened, tell the worker clearly what they're accused of, give them a chance to respond — in a household this can be a calm, documented conversation rather than a formal tribunal — and only then decide. For most misconduct, dismissal should be the last step after progressive discipline (verbal then written warnings), reserved for serious cases or repeated offences. Theft, violence or gross dishonesty may justify dismissal on a first offence, but the worker must still get to put their side.
Incapacity and retrenchment are different
Poor performance is incapacity, not misconduct: the fair route is to point out the shortfall, give guidance and a reasonable chance to improve, and dismiss only if it doesn't. Ill-health incapacity requires considering accommodations before dismissal. Retrenchment (the role genuinely disappears — you're emigrating, or no longer need help) has its own consultation process and is the only reason that attracts severance pay (one week per completed year).
If you get it wrong
A worker who believes their dismissal was unfair — in reason or process — can refer the matter to the CCMA, generally within 30 days. The CCMA can order compensation (up to about 12 months' pay) or reinstatement. Keeping a written record of warnings, the allegation, the worker's response and your decision is the single best protection. Even on the worker's last day you still owe notice (or pay in lieu), all wages, accrued leave and a certificate of service. Compliance tool, not legal advice.