Can I use my younger spouse's age to calculate my RRIF minimum withdrawal?

Yes. A RRIF holder can generally elect to calculate the mandatory minimum withdrawal using a younger spouse's or common-law partner's age instead of their own, and doing so reduces the minimum amount you're required to withdraw each year, since the age-based formula produces a lower percentage at a younger age.

This is a genuinely useful, and often underused, planning tool for a couple with an age gap, because it lets the RRIF holder keep more money growing inside the plan for longer, rather than being forced to withdraw and pay tax on a larger minimum amount based on their own, older age. The catch is timing: this election generally needs to be made when the RRIF is first set up, not added on later once withdrawals are already underway, so it's not something you can simply decide to switch to partway through if you didn't elect it at the outset. If you're setting up a RRIF and you have a younger spouse or partner, it's worth raising this election with your financial institution at the time of conversion, since missing that window can mean losing access to a straightforward way to reduce your mandatory withdrawals for years to come.