Ruling 1934
If a few people are partners, the one whose share reaches the first niṣāb must give zakat. Zakat is not obligatory for those whose shares are less than the first niṣāb.
-Ayatullah Sistani, Practical Laws of Islam, Alms Tax (Zakat)
Alms Tax: Zakat in Partnerships
Practical Laws of Islam as per the teachings of Ayatullah Sistani
