How is Zakat paid on business assets that have reached the Nisab, if one of the partners has taken his share of the profit, but the entire deal has not been sold to the others?

Zakat on partners in trade or wealth—excluding livestock—is incumbent upon each of them for their share if it reaches the nisab and a year has passed over it, even if by combining it with other cash and trade goods they own. The wealth of one partner is not combined with the wealth of another to complete the nisab. The madhhab (school of thought) is that the partnership (mixing) of partners in non-grazing animals (non-livestock) does not affect the ruling, and their ruling is like that of individuals.

Therefore, it is obligatory for each one of them to appraise their share in the company when a year has passed over it. If it reaches the nisab (approximately 85 grams of gold or 595 grams of silver), its Zakat becomes obligatory, and its amount is 2.5%.