How Should One Pay Delayed Zakah?
First of all, you have to know that zakah is one of the pillars of Islam. The Prophet (peace and blessings be upon him), said, “Islam is built upon five pillars: testifying that there is no true god except Allah and that Muhammad is the Messenger of Allah, performing Prayer, paying zakah, making the pilgrimage to the Sacred House (Hajj), and fasting the month of Ramadan.” (Al-Bukhari)
Zakah is the right of the poor on the wealth of the rich, and it must be paid on time. Delaying it is prohibited according to the Sharia (i.e., Islamic Law). In fact, delaying its payment incurs a severe punishment from Almighty Allah, unless the person repents to Him and seeks His forgiveness. Therefore, whoever did not pay zakah of the past years has to count all the previous amounts of zakah that he should have paid in those years after which he distributes this amount among amongst its rightful beneficiaries. In addition, he should seek Allah’s forgiveness since the door of repentance is always open.
In his addressing this issue, Dr. Monzer Kahf, a prominent economist and counselor, affirmed that whoever did not pay zakat for the previous years should pay it as soon as he can and as much as he can along with repenting and seeking forgiveness from Almighty Allah. He should also try to do good deeds as much as he can, such as prayers and especially giving charity, no matter how small it may be, because it protects the person who gives it from the Fire.