Zakaah on real estate shares should be paid as zakaah on trade goods, because these real estate companies buy land with the aim of trading in it.
When the year ends, you have to work out the value of your shares in this company and pay zakaah on them at a rate of one quarter of one tenth.
The year begins from when you took possession of wealth that reached the nisaab, with which you bought these shares.
Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said concerning land that belongs to a real estate company:
These shares are trade goods, it seems, because those who buy shares in land intend to trade and earn money from it. Hence they have to pay zakaah on it every year, by working out its value, then paying zakaah. So if he bought shares for thirty thousand and at the end of the year these shares are worth sixty thousand, then he has to pay zakaah on sixty thousand. If at the end of the year the thirty thousand is worth only ten thousand, then he only has to pay zakaah on ten thousand. End quote from Majmoo’ Fataawa Ibn ‘Uthaymeen (18/226).
He (may Allaah have mercy on him) was also asked about a person who bought land with the aim of trading it, but it remained in his possession for a long time. Does he have to pay zakaah on it?
He replied: If a person buys land to trade it then he has to pay zakaah on it every year, whether its value increases or decreases, and whether he manages to sell it or not. He should work out its value every year, then if he has money he can pay the zakaah from the money that he has. If he does not have money then he should keep a record of the zakaah that is due every year, and when he sells it he should pay the zakaah for the past years. End quote from Liqa’ al-Baab il-Maftooh (15/12).
But if the land or shares do not sell, and the owners put them up for sale but do not find anyone to buy them, then some of the scholars think that in this case it is like a loan that was given to a poor person who cannot afford to pay it off; zakaah is not due on it until it is sold, and he should pay zakaah for one year only. But in order to be on the safe side, he should pay zakaah for all years.
See: Majmoo’ Fataawa al-Shaykh Ibn ‘Uthaymeen (18/206).
And Allaah knows best.