In a Mudaraba contract, zakat on the profit generated by the investment, will be payable by the capital owner.
If the investment manager is considered as a Mudarib, then he will not pay zakat on his share of the profit until it is distributed to him, and one lunar year has passed subsequently. This is the opinion of the Hanafis, Hanbalis, and one opinion of the Shafi’is.
However, according to the prevalent opinion of the latter, zakat will be payable by the investment manager as soon as the profit has been generated, even prior to its distribution.
According to the Malikis, the investment manager will pay zakat as soon as he receives his share of the profit.
If the investment manager is not a Mudarib but a Wakeel who receives a wage for his service, zakat will be payable only on the residual wage that he has left on his zakat anniversary date.
And Allah knows best!
(Mufti) Billal Omarjee