Is zakat due on the principal amount or only on the profits in the case of a partnership with an unknown person to whom I sent money for investment, and I received the profits after five months?

The profit is subject to Zakat (definition) along with the principal if a year has passed over it, and if it reaches the Nisab (definition) by itself or when combined with other money or trade goods. The profit follows the principal, and it is not a condition for a year to pass over the profit specifically. The year begins when the money reaches the Nisab, which is equivalent to 85 grams of gold, or the value of 595 grams of silver. The amount that must be paid is two and a half percent (one-quarter of a tenth) of the principal and the profit.