Having fixed salary and weekly over time pay being tax according to SARS tax table will they owe SAR

I run an nursing agency were I pay the staff weekly some do have permanent jobs and some don't. For the ones which have permanent jobs having salary end of the month will they owe SARS?

It depends on their individual circumstances. They can use our Tax refund calculator to get an idea and then Register for TaxTim and let us help complete and submit their returns for them to SARS.