Are foreign students required to pay tax on their earnings for part-time work?

My son is a foreign student studying for his degree at a South African University. He has a valid Study visa and is permitted under this visa to work 20 hours per week. His employer wants to pay him a salary of R10,000 per month. Firstly does my son have to pay tax on this and if so, how does he register with SARS without a SA Identity document?

Your son is liable to pay tax on this income as the gross will exceed the R75000 tax threshold. He is able to register for tax with SARS by taking along his passport instead of a local ID document.