If the debt is deferred & payable later, then pay the missed Zakat first. However, if the debt is immediate or in the near future and it is feared that by paying missed Zakat you will not be able to pay the debt, it will be permissible to delay the missed Zakat payment. Make a firm intention to pay the missed Zakat as soon as you have the funds available.

The ideal situation would be to pay the missed Zakat from now in small amounts in instalments in a manner that will not affect the debt payment.

And Allah knows best!

Mufti Faraz Adam