Their parents invested wealth for them but they did not pay zakaah on it. What should they do?
Question

                I am a young man, twenty-six years old. My father invested money for us in a mudaarabah (investment) company, and I did not know about it until now. When I saw the mudaarabah contract, one of its clauses said the following: 

The mudaarib (investor) must pay the zakaah on his wealth himself. 

My question is: what is the amount of zakaah that I have to pay, because this investment was made twenty-four years ago and no zakaah has been paid on it? 
Must it be paid from the same capital that was invested, or is it permissible to pay it from somewhere else, as I am working and have an income?.
Praise be to Allah.Firstly: 
You stated 
    that this money was invested in a mudaarabah company, but not all kinds of 
    wealth that are put into company shares are subject to zakaah. Rather the 
    matter is subject to further discussion. We have discussed that in the 
    answer to question no. 69912. If zakaah is due on this wealth, then you must 
    hasten to pay it and we ask Allaah to accept it from you. 
Secondly: 
Delaying 
    payment of zakaah, whether that is for a valid reason or otherwise, is not 
    waived with the passage of time, because it is a right that Allaah has given 
    to the poor and needy, and the others who are entitled to it. 
Al-Nawawi 
    said in al-Majmoo’ (5/302): 
If many 
    years have passed and he has not paid zakaah on it, he must pay zakaah on 
    all of it. End quote. 
It says in
    al-Mawsoo’ah al-Fiqhiyyah (23/298): 
If many 
    years have passed in which the one who was obliged to pay zakaah did not pay 
    it, but the conditions of it being obligatory were met, no part of it is 
    waived, according to scholarly consensus and he must pay zakaah for all the 
    years that have passed when he did not pay zakaah. End quote. 
See also 
    question no. 69798. 
What you 
    must to is hasten to pay zakaah for all the years that have passed before 
    you procrastinate further. 
The ruling 
    does not differ, whether this wealth belongs to your father or it belongs to 
    you and he invested it for you, because zakaah is due in both cases. 
Shaykh Ibn 
    ‘Uthaymeen was asked about a man who died and owed zakaah: should it be paid 
    and given priority over division of the state?
 He 
    replied: 
If this man 
    used to pay zakaah during his lifetime, but a full year had passed when he 
    died (for which he did not pay zakaah), then his heirs must pay zakaah, 
    because the Prophet  (peace and blessings of Allaah be upon him) said: 
    “Pay off the dues of Allaah, for the dues of Allaah are most deserving of 
    being paid off. 
But if he 
    deliberately did not pay zakaah and withheld it out of stinginess, then this 
    is a matter concerning which the scholars differed. In order to be on the 
    safe side – and Allaah knows best – the zakaah should be paid, because it 
    has to do with the rights of those who are entitled to zakaah and is not 
    waived. The rights of those who are entitled to zakaah take precedence over 
    the rights of the heir with regard to this wealth, but the duty of the 
    deceased is not discharged in this case, because he persisted in not paying 
    it. And Allaah knows best. 
Majmoo’ 
    Fataawa Ibn ‘Uthaymeen, 18/no. 43. 
Thirdly: 
There is 
    nothing wrong with paying zakaah from wealth other than that on which zakaah 
    is due, such as if you pay it from your salary or otherwise. This has been 
    stated by the scholars. 
Ibn Qudaamah 
    said: 
Paying 
    zakaah from something other than the nisaab is permissible. 
Al-Mughni, 
    2/287 
Some of the 
    scholars narrated that there was consensus on this point. ‘Abd al-‘Azeez ibn 
    Ahmad al-Bukhaari said: According to consensus, it is permissible to pay the 
    share of the poor from something other than the nisaab. 
Kashf 
    al-Asraar, 3/370 
And Allaah 
    knows best.