Tax on leave buyback?

A client called asking if this is correct. Having never heard of this, and after trolling the SARS website I could find no reference to buyback of annual leave.
I googled and found correspondences to old payroll and HR explanations (2009-2010) saying it's deemed a bonus and thus taxed at 50 to 55% tax (??? really not sure how valid this is)

That is incorrect, the highest marginal tax bracket is only 40% and the employer could withhold that percentage, but it will reverse out at the time of filing. Else apply for a tax directive of the lesser percentage.

As for 50%, we are not aware of anything like that.

Thank you so much for your confirmation - I didn't think it was correct, but because I couldn't find anything definitive I wanted another's opinion

Only a pleasure!