Is zakat obligatory on a sum of money inherited by children from their father, which remained with their uncle for 13 years, and what is the amount of zakat due on it?

Safeguarding the wealth of orphans is an obligation upon the state and guardians, as Allah Almighty says: "And do not give the foolish your wealth, which Allah has made a means of support for you" (Quran 4:5).

Zakat (definition) is obligatory on the wealth of a child, an orphan, and an insane person, and it is calculated after a year has passed from the death of the inheritor.

As for the Zakat due on inherited wealth, it is divided into two categories:

First: The wealth of mature, non-orphan heirs: There is no Zakat on it except when it is received, and it is subject to Zakat for one year only because it was withheld. If an heir dies before receiving their wealth, there is no Zakat due from them.

Second: The wealth of orphans: Zakat is due on it for all past years because its retention by the guardian is not considered usurpation. It is also recommended to engage in trade with the orphan's wealth.

Method of Zakat calculation: The share of each orphan is calculated, and its Zakat for the past years, from the death of the father until puberty, is paid. After puberty, if the orphan is of sound judgment and has not been given their wealth, the wealth becomes like usurped property, and there is no Zakat on it except after it is received, whereupon it is subject to Zakat for one year.

The amount of Zakat that must be paid is 2.5% annually.

The guardian must repent for withholding the wealth of adult heirs and pay the grandfather's share to his heirs.