line 122 and line 421 a huge difference in Notice of assessment. Can someone help me understand please.
I did a client's multiple year (2011-2017) self employment return. When the assessment came, there was a huge difference between the amount in line 222 CPP (i.e $709) to line 421 (i.e $4435) which should be approximately $1420. This pattern continues for each year from 2011-2015. The self employment income (after expense is pretty much the same range (from $18000-24000 for different years). I can not figure out why is so much difference. Can someone help me understand.
I have attached a copy of one of the year NOA-2011