Does everyone need to be registered for tax?

No, you would not need to as you earn less than the taxable threshold (R63 556 per year for 2013 tax year), however some institutions like banks request Tax Clearance certificates which can only be obtained if you are fully tax compliant. So it might be best to register anyway and complete your annual tax return - you won't end up paying any tax but you will have a clean record in the eyes of SARS.

Here is a quick guide to registering for a SARS tax number.