Does the undertaking length differ for sponsoring a spouse versus sponsoring a parent or grandparent?

Yes, the undertaking length is very different depending on who is being sponsored. A spousal, common-law, or conjugal partner sponsorship comes with an undertaking that runs for 3 years from the day the sponsored person becomes a permanent resident. A parent or grandparent sponsorship comes with a much longer undertaking of 20 years from that same milestone — the day the sponsored person becomes a permanent resident, not the day the application was filed or approved.

That distinction in timing matters a lot, because processing can take a long time, and the clock doesn't start counting down while the application is still being decided. It only begins once permanent residence is actually granted, so a sponsor's real commitment period is measured from that specific date forward, whichever category applies to them.

The difference in length reflects the different nature of these relationships in the eyes of the sponsorship framework, and it's fixed by category rather than something a sponsor can choose or adjust. If you're considering sponsoring a spouse, partner, parent, or grandparent, it helps to go in with a realistic understanding of exactly how long your financial undertaking will run, since it's a serious, long-term commitment either way. An immigration lawyer can walk you through what this means for your specific situation before you sign anything.