Tax due on extra income

I receive an extra income of R3640 per month - for the year it was R43 680. 00

What is the tax implications for this? I am not taxed monthly, but will it make a huge difference on my tax return for 2016?

The extra income will make a difference, you can use our SARS income tax calculator to check what your additional tax will be, remember to add all your incomes together when you use the calculator.