Is zakat obligatory on an investment sukuk amount that has reached the nisab and on which zakat has become due, and which is invested in Abu Dhabi Islamic Bank under a three-year sukuk system with a monthly return, knowing that a car was purchased with this sukuk as collateral and its installments continue for five years, where the monthly return from the sukuk is used and an amount from the salary is added to complete the installment, and that the bank renews the sukuk to guarantee its right until the installments end, and thus the original amount cannot be utilized until the full installments are paid?

It is permissible to mortgage certificates (sukuk) if their issuance and trading are Islamically permissible, such as Islamic sukuk and shares of companies with halal activities. Mortgaging usufruct certificates is also permissible.

Regarding zakat, there is no zakat on the returns that are consumed in paying installments before zakat becomes due. However, the value of the certificate is subject to zakat every year.

If the debt (car installments) consumes the zakatable threshold (nisab) or reduces it, then there is no zakat on the value of the certificate, unless other funds are available that exceed one's needs and can be allocated to cover the debt.

The fact that the certificates are mortgaged to the bank does not prevent zakat according to the majority of scholars, such as the Shafi'is and Hanbalis. This is the preponderant opinion because ownership of the wealth does not transfer with mortgaging.