RSP Tip 1. Know you marginal tax rate. One of the most important benefits of the RRSP is the tax deduction for the current tax year. While most people put money into the RRSP to save tax, many do not know how much tax they are saving. The easiest way to determine the benefit of your RRSP contribution is to know what your current marginal tax rate is when you combine the federal and provincial taxes. #F55#RSP#RetirementPlanning