How can I pay the zakat on my wealth, after I used to pay it only from the profits due to my ignorance, and not from the principal capital?

The merchant must appraise his goods at the end of every Hijri year and pay their zakat, which is two and a half percent, if their value reaches the minimum threshold (nisab). Zakat is due on both the capital and the profit. Any missed zakat from previous years remains a debt on one's conscience and must be paid immediately, along with seeking Allah's forgiveness for negligence in learning religious rulings.