How to Report Rental Income From a Basement Suite

Renting out a basement suite is straightforward to do and less straightforward to report. Most of it is mechanical — a form, some proration, a set of deductible expenses. But sitting underneath the mechanics is one consequential issue that doesn’t surface until you sell your home, sometimes a decade later.

This guide covers how the reporting works, what you can and can’t deduct, the distinction that decides when a cost is deductible, and the principal residence issue that’s worth understanding before you build rather than after.

How do you report rental income from a suite?

Rental income from a suite in your own home is reported on Form T776, Statement of Real Estate Rentals, filed with your personal income tax return. The form captures gross rental income, your deductible expenses, and the resulting net rental income or loss, which flows through to your return.

Income means what you actually received in the tax year — rent, and generally any additional amounts the tenant pays you.

Expenses are prorated. This is the central mechanic when you rent part of your own home. You can only claim the portion of whole-property expenses that relates to the rented space. If the suite represents 30% of your home’s total square footage, you can generally claim 30% of the property-wide expenses.

The apportionment has to be reasonable and consistently applied. Square footage is the most common and most defensible basis. Number of rooms is sometimes used. Whichever you choose, use the same method year to year and be able to explain it — this is exactly the kind of figure that gets questioned.

One further point on losses: where you rent part of your own home, the CRA’s position is that you may only write off rental losses against your other income where there is a reasonable expectation of profit from the rental. A structurally loss-making arrangement — renting to a relative well below market, for instance — may not support a loss claim.

What can you deduct?

Broadly, the rented share of the costs of running the property.

Commonly deductible (prorated):

• Mortgage interest — the interest portion only
• Property taxes
• Home insurance
• Utilities, where you pay them for the rented space
• Repairs and maintenance
• Condo or strata fees, where applicable
• Advertising for tenants
• Professional fees relating to the rental

Not deductible:

• Mortgage principal. Only the interest is deductible — the principal portion of your payment is repaying a debt, not an expense.
• The value of your own labour. If you do the maintenance yourself, you cannot assign a wage to your time.
• Expenses relating to your personal living space, which is what the proration is separating out.

The mortgage principal point catches people every year. Your monthly payment is a blend of interest and principal, and only one part of it is an expense for tax purposes. Your lender’s annual statement will separate them.

Current expenses vs capital expenses

This distinction decides when you get the benefit of a cost, and it comes up constantly with suites because a lot of suite work sits near the line.

A current expense maintains the property in its existing condition. It’s deducted in the year you incur it. Repairing a leaking tap, repainting, fixing a broken window, servicing the furnace.

A capital expense improves the property beyond its original condition, or gives a lasting benefit. It isn’t deducted immediately — it’s added to the property’s cost base, which reduces the capital gain when you eventually sell.

Rough tests: does it restore the property to its previous state, or make it better than before? Is the benefit short-lived or enduring? Is it a repair to an existing asset, or a new asset entirely? Replacing a few damaged tiles is current; replacing the whole floor with a superior material is likely capital.

Most of the cost of building the suite itself is capital. Creating a separate entrance, installing a kitchen, framing new walls — that is construction, not maintenance, and it belongs in the cost base rather than in the current year’s deductions.

Capital cost allowance is optional — and it has consequences. CCA lets you claim depreciation on the building portion over time, producing a deduction now. Two reasons to be careful before you do:

1. Claiming CCA can create a recapture and increase your taxable gain when you sell.
2. Claiming CCA blocks certain deferral elections under the change-of-use rules, and — as the next section explains — it is one of the three conditions in the CRA’s principal residence safe harbour.

For most homeowners renting part of their own home, claiming CCA is a short-term gain traded for a longer-term cost. It is a decision worth taking deliberately with an accountant, not by default because software offers it.

The principal residence exemption risk

This is the section worth reading twice, because it’s the one that shows up years later.

Normally, the principal residence exemption shelters the gain on your home when you sell it. Renting part of it out can put a portion of that shelter at risk.

The CRA’s guidance — in its T4036 Rental Income Tax Guide and Income Tax Folio S1-F3-C2, Principal Residence — is that you are not considered to have a change in use, provided all three of the following are true:

1. The part of the home used for rental purposes is small in relation to the size of the whole property
2. You make no structural changes to the property to make it more suitable for rental purposes
3. You claim no capital cost allowance on the part used for rental

Meet all three, and you won’t have to report a capital gain on the rented portion when you sell or when the rental stops. Fail any one of them, and you report a capital gain based on the portion of the house that was rented.

Here is why this matters so much for suites specifically. Structural changes are described as more permanent alterations — installing a separate entrance or a kitchen, or adding, moving or removing walls. Those are precisely the things that make a suite self-contained and legal. So a homeowner who builds a proper secondary suite has typically made a structural change, and falls outside the safe harbour.

Renting a spare bedroom to a boarder with no modifications and no CCA claimed is the situation the safe harbour was written for. Building a self-contained legal suite generally is not.

What that means in practice. A change in use triggers a deemed disposition of the affected portion — you’re treated as having disposed of it and immediately reacquired it at fair market value. Elections exist that can defer a resulting gain, including one under subsection 45(2) of the Income Tax Act, but it is unavailable if CCA has been claimed. Where a valuation is needed, a professional appraisal at the time of the change is far more defensible than a reconstruction years later.

None of this is a reason not to build. The rental income and added property value usually outweigh it comfortably, and a legal suite is worth far more than an unpermitted one. But it should be a decision you make knowingly, with advice, before construction — not something you discover on closing day.

Records to keep

Rental reporting is document-driven, and reconstructing records after the fact is the expensive way to do it.

• Lease agreements and a record of rent received
• Your annual mortgage statement, showing the interest/principal split
• Property tax and insurance statements
• Utility bills, where you pay for the rented space
• Every receipt and invoice for repairs and improvements, with vendor details and dates — you’ll need to sort them into current and capital eventually
• Your apportionment calculation — the square footage figures and how you arrived at the percentage. Write it down once and reuse it.
• An appraisal, if a change in use occurs, dated at the time of the change
• Permits and inspection records for the suite

Keep capital expense records for as long as you own the property. They reduce your gain on sale, and only if you can evidence them.

When to get an accountant

Three moments specifically:

Before you build. The change-in-use question, whether to claim CCA, and how the project is structured are all decided at the outset. This is the highest-value hour of professional time in the whole process.

In your first year of reporting. Getting the apportionment method and the current/capital split right once means repeating it correctly thereafter.

Before you sell. If any part of your home has been rented, the principal residence position needs to be worked out properly. Note that where a property was partly rented, a Principal Residence Designation may need to be filed with your return on sale, and late filing can attract penalties.

Our secondary suites overview covers the building side, our FAQ answers common questions about the process, and our financing and grants guide covers what support is currently available.

Plan the suite before you build it

Most of the tax outcomes above are set by decisions made before construction starts — how the unit is configured, whether it’s genuinely self-contained, and how the project is structured.

HouseLyft’s free property assessment establishes what your property can support and what configuration makes sense, so you can have the tax conversation with real specifics rather than hypotheticals. Request your free report.