How is Zakat deducted from a fixed amount of 200,000 dirhams in a bank?

If the aforementioned money reaches the nisab (minimum threshold), zakat becomes obligatory on it every year, as long as it does not fall below the nisab, even if it does not increase. Zakat is obligatory on cash because it inherently possesses the potential for growth. Growth in Islamic law is of two types: actual growth, which is an increase in wealth, and estimative growth, which is the owner's ability to achieve an increase. Zakat is obligatory on the two precious metals (gold and silver) because they are prepared for trade and growth. As long as the money is in the bank and accessible, it is zakat-eligible wealth, and zakat becomes obligatory on it upon the passing of a full Hijri year, at a rate of 2.5 percent. If the zakat for previous years has not been paid, it must be calculated and disbursed.