Hi guys, dunno should i ask here or not but need some advice. Recently my dad receive a warning letter regarding income tax due around rm 1.6k from hasil.gov haven't paid for year 2000~2006. We were shocked because during those year, his salary not even reach rm2k. So he went and ask today, and they said it was for year 1987~1990 when he still own a medicine store before it went bankrupt. I think he didn't declare salary at that time because I doubt he know he need to declare it since the store actually belong to my grandfather, but register under my dad's name. So should he pay for it since already pass more than 20 years? Or is there any other method to settle this since the store went bankrupt?