All perfect praise be to Allaah, The Lord of the worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and messenger.
The unemployment of a person does not exempt him from the obligation of paying Zakah on money he owns if it reaches the Nisaab and one full lunar year passes on it. Based on this, you have to hasten to pay the Zakah on your money for all the years that have passed since the money reached the Nisaab and after the first full lunar year had passed on it. You have to exert effort in calculating the correct amount of Zakah and be cautious so as to free yourself of any liability. To achieve this, you have to detect the year in which the money had reached the Nisaab. If you are not sure whether it was five or six years ago, for example, then you are required to pay Zakah for five years but, to be more prudent, pay it for six years.
You also have to do your best in calculating the amount the money had reached every year. If you are not sure whether it was, for example, 80,000 or 100,000 in a certain year, then estimate it as 100,000 out of prudence. You have to do so regarding all the years and then calculate the Zakah for each year separately. Thus, you will have done what is within your capacity as Allaah Almighty Says (what means): {Allaah Does not Charge a soul except [with that within] its capacity} [Quran 2:286].
We ask Allaah Almighty for help and acceptance, for us and for you.
Allaah Knows best.