Apply RA tax deductible to provisional tax payment or get a refund after the final tax submission

I am a provisional tax payer and contributing the maximum allowed deductible to an RA (15% of non-retirement funding income). I would like to know whether I can deduct this from the taxable income myself for the provisional tax payment, meaning I pay less to SARS now and do not get a refund later, or whether I should pay tax on the full income without deducting the RA deductible and then get a refund from SARS later on? If I have a choice, I would prefer not overpaying taxes to SARS and aim for a zero refund (or additional pay-in) to SARS with the final submission.

You can deduct it now when calculating your provisional tax.
Please read our blog on What is Provisional Tax? How and when?