RE: Big jump today....I don't believe there is. If you're an employee, your employer is obligated to deduct taxes at source. However, you can ask your employer to reduce your taxable income by the amount of the RRSP deduction you made at the beginning of the year (I don't recall the form #). If you declare yourself as self-employed you'll still have to make monthly or quarterly tax installments based on the lower of your taxes last year or this year. As self employed you'll have to pay both employee and employer CPP but not UIC and you'll probably lose all your employee benefits such as healthcare insurance and pension contribution. However, all this is moot if you do not qualify as self employed (i.e. employer tells you what to do, when to do it and gives you the tools to do your job).