Paying zakaah ahead of time and how to pay zakaah if his money is in the Islamic bank
Question

                I have an amount in an Islamic bank. Is it permissible for me to pay Zakat in advance during the year? Like when I receive interest; as I fear when the time of paying it comes, I will not have money to pay it. 

Do we give Zakat out of the capital only or of capital and interest together?.
Praise be to Allah.
    Firstly: 

    It is not permissible for a Muslim to invest his wealth in a 
    riba-based bank, or that which is called Islamic but is not, rather it 
    should be Islamic in nature as well as in name. If the bank is Islamic and 
    does not deal in riba by taking or giving interest, and it invests its 
    wealth and distributes the profits to the investors in accordance with the 
    rulings of Islamic sharee’ah, then there is nothing wrong with investing 
    money in it. 

    See also the answer to question no.
    47651 

    Secondly: 

    With regard to paying zakaah in advance, the correct view is 
    that it is permissible, and this is the view of the majority of scholars, 
    but it is better not to pay zakaah in advance, unless there is a reason for 
    doing so. 

    Shaykh al-Islam Ibn Taymiyah (may Allaah have mercy on him) 
    said: As for paying zakaah before it  is due, that is permissible according 
    to the majority of scholars, such as Abu Haneefah, al-Shaafa’i and Ahmad, 
    and it is permissible to pay zakaah in advance on livestock and gold and 
    silver, and trade goods, if he owns the nisaab (minimum threshold). End 
    quote. 

    Majmoo’ al-Fataawa (25/85, 86) 

    The scholars of the Standing Committee for Issuing Fatwas 
    said:  

    There is nothing wrong with paying zakaah one or two years in 
    advance, if that will serve an interest, and giving it to the poor and needy 
    on an annual basis. End quote. 

    Shaykh ‘Abd al-‘Azeez ibn Baaz, Shaykh ‘Abd al-Razzaaq 
    ‘Afeefi, Shaykh ‘Abd-Allaah ibn Ghadyaan.  

    Fataawa al-Lajnah al-Daa’imah 
    (9/422). 

    Shaykh Muhammad ibn Saalih al-‘Uthaymeen (may Allaah have 
    mercy on him) was asked: 

    What is the ruling on paying zakaah for several years in 
    advance to disaster victims? 

    He replied: 

    Paying zakaah more than a year in advance is valid, but it is 
    only permissible for a few years, and it is not permissible for more than 
    that. But one should not pay zakaah in advance unless it is in response to a 
    need such as a severe famine or jihad and the like. In that case we say that 
    it should be paid in advance, because there may be reason to make what is 
    ordinarily less appropriate more appropriate,  otherwise it is better not to 
    pay zakaah until it becomes due, because something could happen to his 
    wealth of destruction and the like. Whatever the case, it should be noted 
    that if he subsequently has more than he had when he paid in advance, zakaah 
    must be paid on the additional amount. 

    Fataawa al-Shaykh al-‘Uthaymeen 
    (18/328). 

    Thirdly: 

    Zakaah must be paid on all the money – both the capital and 
    the profits – when one year has passed from the time when the capital was 
    acquired and reached the nisaab. The year in question is a hijri year. 

    The scholars of the Standing Committee for Issuing Fatwas 
    were asked: 

    I have some wealth worth fifteen thousand riyals (15,000) 
    which I gave to a man to do business with, on the basis that he would have 
    half of the profits. Is any zakaah due on this money? Which should I pay 
    zakaah on, the capital, the profit or both? If zakaah is due on the capital 
    and we bought goods with the capital such as carpets, furniture and the 
    like, what is the ruling in that case? 

    They replied: 

    Zakaah is due on the wealth mentioned which has been prepared 
    for trade, when one year has passed. Zakaah should be paid on the capital as 
    well as the profits when one year has passed, even if the money was used to 
    buy trade goods. Their value should be worked out based on the market price 
    at that time, when one year has passed, and zakaah should be paid at a rate 
    of two and half percent (2.5%) on the total wealth, including the profits. 
    End quote. 

    Shaykh ‘Abd al-‘Azeez ibn Baaz, Shaykh ‘Abd al-Razzaaq 
    ‘Afeefi, Shaykh ‘Abd-Allaah ibn Ghadyaan. 

    Fataawa al-Lajnah al-Daa’imah 
    (9/356, 357) 

    They also said: 

    Zakaah must be paid on the capital and profits when one year 
    has passed since the wealth was first acquired (the capital). The year for 
    the profits is the same as the year for the original capital. End quote. 

    Shaykh ‘Abd al-‘Azeez ibn Baaz, Shaykh ‘Abd al-Razzaaq 
    ‘Afeefi, Shaykh ‘Abd-Allaah ibn Ghadyaan. 

    Fataawa al-Lajnah al-Daa’imah 
    (9/356, 357)                             

    We should also point out that if the Islamic bank pays zakaah 
    on behalf of its customers, that is sufficient and he does not have to pay 
    zakaah, if the bank can be trusted to do that in the proper Islamic manner, 
    but he still has to pay zakaah on that which is in his possession and that 
    which he owns, which is not in the bank.