Yes. Each subordinate is required to provide his/her own ‘Authority on Special Power of Attorney by Tax Practitioner’ form.
For Example:
In a case where the authority is granted to a consulting firm (e.g. Deloitte); each consultant must have an ‘Authority to Special Power of Attorney by Tax Practitioner’ form from the tax practitioner who signed the SARS ‘Special Power of Attorney to Tax Practitioner’.