Spousal RRSPs can greatly reduce taxes in retirement because you???ll likely pay less tax by withdrawing the same amount of income from two smaller incomes than from one large one. i.e. if one spouse has CPP, a company pension plan, and an RRSP, the taxes payable will be higher with 3 forms of income than if the other spouse instead had the RRSP. With a Spousal RRSP, you can still defer taxes now