I see this topic being discussed on Reddit every tax season. I get calls about this all the time. People previously changed their principal residence to a rental property years ago, but their previous tax preparer failed to notify them of their obligation to file Form T2091. Now, they're calling me to tell me they sold their rental property, and the capital gains tax could cost them 10s or 100s of thousands in tax.
If you found this article online, you need to seek the expertise of a CPA in Ottawa before the CRA catches on.
Typical scenario I have resolved for clients: Someone moves out of their house, rents it out, and years later realizes they may have missed something important on their tax return. They changed the use of their principal residence into a rental property, but never reported the deemed disposition and never filed Form T2091. It can become a problem because when you convert a principal residence into a rental, CRA generally treats that as a change in use.
The "change in use" usually creates a deemed disposition at fair market value on the date of the change. In plain English, CRA acts like you sold the property to yourself and bought it back the same day.
Usually, the increase in value during your time living in the house up to that date can still be sheltered by the principal residence exemption. But CRA still expects the disposition to be reported, and they change penalties if you don't.
Scenario:
You purchased your first home in 2019 for $400K. In 2025, you bought your second home and converted your first one into a rental. At the time you converted your first one into a rental, it was worth $500K. That's $100K of increase that you'd have to pay capital gains tax on, except if it was your principal residence. The only catch is, you MUST notify CRA when you file your taxes in 2026. If you don't the CRA can charge you significant penalties. This isn't something new, it's been a rule for at least 10 years now.
Before 2016, many people did not report principal residence dispositions at all if the full gain was exempt, but CRA changed that. Since the 2016 federal budget, principal residence dispositions have to be reported on Schedule 3, and usually supported with Form T2091 when needed.
So this is not a new rule anymore. It has been almost 10 years.
References that I see online:
Most homeowners are not thinking about tax forms when they move out and start renting a former home, and their tax preparer is not experienced enough to provide advice. They are thinking about tenants, repairs, mortgage payments, and insurance. Then years later, when they sell the property, someone finally asks:
“When did this stop being your principal residence?”
That is when the missing T2091 issue shows up.
And yes, people talk about this on Reddit every few months, this is another post I found:
https://www.reddit.com/r/cantax/comments/1pfsocc/cra_fines_late_t2091_primary_residence_to_rental/
I’ve seen the Reddit comments saying CRA probably would not assess penalties in this situation. Maybe. Maybe not.
But if CRA wants to, you could be facing the following.
Late filing can result in:
The legislative reference for the late designation penalty is subsection 220(3.21) of the Income Tax Act, which allows CRA to charge a penalty equal to the lesser of:
So no, I would not rely on “CRA probably won’t care.”
If you missed the deadline:
Contact CRA Immediately
You may qualify for taxpayer relief provisions, which generally have a 10-year window.
Submit a Voluntary Disclosure
This can reduce penalties and show good faith, depending on the facts.
Work with a Tax Accountant
A tax accountant helps make sure the change in use is reported properly, the principal residence years are documented, and any elections are handled correctly.
In some cases, when a principal residence becomes a rental, you may be able to elect under subsection 45(2) to defer the deemed disposition.
That can preserve the principal residence exemption for up to four more years, even while the property is rented. This is a typical situation for somebody who moved back in with their parents or moved to rent their own apartment, and converted their principal residence into a rental property. But that election needs to be handled properly. It is not something I would leave to chance.
If you changed your principal residence into a rental and forgot to file Form T2091, do not assume it is harmless just because nothing happened yet.
CRA changed the reporting rules in 2016. They have had plenty of time to enforce them.
And if they decide to press the issue, the penalties and filing problems can get expensive fast.
Better to fix it before the sale, not after CRA asks questions.
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This is not legally binding tax advice. This is educational analysis. Say hello if you need help.
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