Reg sole proprietorship with SARS? or add earnings to personal tax.

I run a very small business (less than R5000 per month) as a sole proprietor in addition working another job. Do I have to register the small business with SARS and do I need to pay taxes each quarter or annually adding both jobs together?

No you do not need to register the business with SARS, you will include that additional income and expenditure in the tax return you submit to SARS as normal. If you make a profit from this business of more than R30 000 each year then you need to register as a Provisional Taxpayer