With how much tax you pay it also depends not only on your business income but the household income - for example I have done my income tax first and I will be eligible for a REFUND and than I do my husbands and go back and add the little section in mine were it says spouses income when I add his suddenly I OWE ... reason being tax credits I was eligible for I loose because as a household our combined income is just over the eligible line ... same with some years we would have owed like $4000 however purchasing a RRSP of a wee bit more than that pushed us into me getting a refund ... so it is so variable for sure!