I recently found out that I’m required to pay Khums on my earnings, but didn’t know about this in the past. I’ve been working and earning for about 4 years now. Should I try and calculate the khums I owe for all 4 years I missed or can I ask for forgiveness for not knowing and pay the khums starting from this year moving forward? I would really appreciate the guidance, I’m not sure I am able to calculate all my expenses from 4 years back but can try if necessary.

You should try to calculate khums from 4 years ago and for each year. Try to estimate. That is the right thing to do.

Here is a booklet that helps you