Yes I do and you do have to. It gets calculated when you do your taxes. I have an accountant who does mine for me but I do know that we have to pay the employer and the employee contribution for CPP as we are self-employed. I automatically put tax and CPP money into a seperate account every time I'm paid and I calculate 10% for the CPP contribution. So far I have not needed all the money I have saved (due to expenses being deducted) but this works well for me.