Renting Out Your Basement Suite in Canada: What CRA Expects (And What Most Homeowners Get Wrong)

Renting out a basement suite is one of the most common ways Canadians offset their mortgage. A few hundred to over a thousand dollars a month in rental income, a tenant downstairs, and a house that more or less pays for itself — it's a sensible arrangement that hundreds of thousands of Canadian homeowners rely on.

It's also one of the most consistently mishandled situations in Canadian personal tax. Most basement suite landlords underreport deductions, miss the mortgage interest split, or don't realize they've created a capital gains exposure on a home they assumed was fully sheltered by the principal residence exemption.

This guide covers everything CRA expects from a Canadian homeowner renting a basement suite — the income reporting, the deductions, the personal use calculation, and the traps that catch people when they eventually sell.

Yes, You Have to Declare It

There is no threshold below which basement suite rental income becomes non-taxable in Canada. If you collected rent — including cash, e-transfer, or any other form — you are required to report it to CRA. The amount doesn't matter. One month, all twelve months, a partial year — it's reportable.

CRA has significant data-matching tools. Property tax records, utility accounts, and municipal secondary suite registrations all help CRA identify properties that generate rental income. The risk of not declaring isn't theoretical.

The good news: the deductions available to you substantially reduce the taxable portion of your rental income. Done correctly, many basement suite landlords owe very little net tax on the income after legitimate expenses are applied.

How CRA Treats a Basement Suite

When you rent part of your home — a basement suite, a secondary unit, an accessory dwelling — CRA treats that portion as a rental property operating within your principal residence. You file Form T776 (Statement of Real Estate Rentals) alongside your T1 personal return. The net rental income or loss from that T776 flows onto your T1 as taxable income.

The key distinction from owning a separate rental property: shared expenses must be allocated between the personal portion (your living space) and the rental portion (the suite). You cannot deduct 100% of costs that benefit both parts of the home.

The Personal Use Calculation: The Foundation of Everything

Every shared expense in your home — insurance, property tax, utilities, mortgage interest, maintenance — must be split between personal use and rental use before you can claim a deduction. CRA's accepted method is square footage.

In this example, the rental portion is roughly 29–43% of the home depending on how you treat shared spaces. A common approach: allocate shared mechanical rooms and laundry 50/50 between personal and rental, then add the suite's exclusive area.

Document your calculation with floor plan measurements. If CRA questions it, your methodology — not your memory — is what they want to see. Measure once, keep it on file.

The rental percentage you establish becomes the multiplier you apply to every shared expense throughout the year. If your rental portion is 35%, then 35% of your insurance premium, property tax bill, and utility costs are deductible as rental expenses.

What You Can Deduct: The Complete List

Mortgage Interest (Line 8710) — The Big One

This is the largest deduction most basement suite landlords have and the one most frequently calculated incorrectly.

Only the interest portion of your mortgage payment is deductible — not the principal. The split changes every month as your balance decreases, so you can't just use the same number all year. Your lender provides an annual mortgage interest statement (usually mailed in January or available online) that shows exactly how much interest you paid during the calendar year. Use that figure.

Apply your rental percentage to the annual interest total. If you paid $18,400 in mortgage interest last year and your rental portion is 35%, your deductible amount is $6,440.

Important: Canadian mortgages compound semi-annually, not monthly like American mortgages. If you're using a calculator or software to estimate your interest, make sure it uses semi-annual compounding — otherwise your split is wrong.

Property Tax (Line 9180)

Your annual property tax bill multiplied by your rental percentage. If your city charges $5,200 annually and your rental portion is 35%, you can deduct $1,820. Keep a copy of your tax notice.

Home Insurance (Line 8690)

Apply your rental percentage to the annual premium. If your landlord insurance policy covers both your personal dwelling and the rental suite as a rider, the portion attributable to the rental coverage may be fully deductible — ask your insurer to separate the premium components if possible.

Utilities (Line 9220)

If you pay for heat, electricity, water, or internet that serves both units, apply your rental percentage. If the suite has its own separately metered electricity, that full cost is directly deductible without the personal use calculation.

Repairs and Maintenance (Line 8960)

Expenses for repairs to the rental suite specifically — plumbing in the tenant's bathroom, replacing the suite's appliances, patching drywall after the tenant moves out — are 100% deductible, no personal use split needed. Only repairs that benefit the whole home (a new furnace, roof repairs) need the percentage applied.

Advertising (Line 8521)

What you paid to list the suite — Kijiji, Facebook Marketplace, a property management platform — is 100% deductible in the year you spent it.

Professional Fees (Line 8860)

Legal fees for drafting a lease or eviction proceedings are deductible. Accountant fees specifically for preparing the T776 portion of your return are deductible. General personal tax preparation fees are not.

Management Fees (Line 8871)

If you pay a property manager to handle the suite, that fee is 100% deductible.

What You Cannot Deduct

Mortgage principal. Only interest is deductible. The portion of your payment that reduces your balance is not an expense.

Personal portion of shared expenses. If your rental portion is 35%, the remaining 65% of property tax, insurance, and utilities is a personal expense — not deductible.

Capital expenditures in the year incurred. A new kitchen in the suite is a capital expenditure, not a current repair. It gets added to the property's capital cost — though see the CCA section below before you decide how to handle this.

The value of your own time. You cannot deduct the hours you spend managing the suite or doing repairs yourself. Only out-of-pocket expenses are deductible.

The Capital Gains Trap Most Basement Suite Owners Never See Coming

This is the most important section of this guide — and the one most people skip until it's too late.

Canada's principal residence exemption (PRE) shelters the capital gain on your home when you sell it. For most Canadians, this is the single largest tax shelter they will ever have access to — a home that doubled in value over 15 years is sold completely tax-free because the PRE applies.

The problem: renting part of your home can affect your eligibility for the full PRE.

The Change in Use Rules

Under section 45 of the Income Tax Act, converting any portion of your principal residence to income-producing use (i.e., starting to rent the basement suite) triggers a deemed disposition at fair market value on the date of conversion. In other words, CRA treats it as if you sold and immediately repurchased the rental portion of the home at that date.

In a rising real estate market, this creates a capital gain — taxable at the time of actual sale — for the appreciation in the rental portion from the conversion date onward.

The Exemption That Often Saves You

CRA provides a specific exception under Income Tax Folio S1-F3-C2 (Principal Residence) that many basement suite landlords qualify for: if the rental activity is ancillary to the main use of the property as a principal residence and you have not claimed CCA on the rental portion, you may be able to designate the entire property as your principal residence for every year you owned it — including the years you rented the suite — and eliminate the capital gain entirely.

The conditions that typically need to be met:

The rental use is incidental. You live in the house as your primary home. The suite is a portion of it, not the other way around.

No structural changes were made to create the suite. If the basement was always a suite (or was converted before you bought), you're generally in better shape. If you specifically renovated to create a rental unit, document the original state.

You did not claim Capital Cost Allowance (CCA). This is the critical one. See below.

Should You Claim CCA on a Basement Suite? Almost Always: No.

Capital Cost Allowance is the depreciation deduction available on rental property. For a rental portion of a home, you can theoretically claim CCA each year — Class 1 at 4% declining balance for the building, Class 8 at 20% for appliances.

CRA's rule: if you claim CCA on any portion of your principal residence, that portion permanently loses eligibility for the principal residence exemption.

This is a trap that looks like a benefit. Claiming $2,000 in CCA this year saves you maybe $700 in income tax (at a 35% marginal rate). But it means that when you sell a home that appreciated by $400,000, the rental portion — perhaps 35% of the gain, or $140,000 — is now a taxable capital gain. At the 2026 inclusion rate, that could cost you $35,000 to $50,000 in tax.

The standard advice from Canadian accountants: do not claim CCA on a basement suite unless you intend to convert it to a fully separate rental property, are prepared to lose the PRE on that portion, and have confirmed the math makes sense for your specific situation. For most homeowner-landlords, the long-term capital gain exposure far exceeds the short-term CCA tax savings.

If You're in Ontario, BC, or Alberta: Zoning and Licensing

Before or alongside the tax question, make sure your basement suite is legal in your municipality. Rules vary significantly:

Ontario: Ontario's Planning Act was amended in 2022 to require municipalities to permit secondary suites as-of-right in most residential zones. However, building permits, fire code compliance, and registration may still be required locally. Toronto has a Secondary Suite Program; Hamilton, Ottawa, and other cities have their own requirements.

British Columbia: BC municipalities broadly permit secondary suites under zoning, but registration and inspection requirements vary by city. Vancouver requires a Secondary Suite Permit and annual fire inspection. Surrey, Burnaby, and Richmond each have their own processes.

Alberta: Calgary and Edmonton have secondary suite programs. Suites that predate bylaw requirements may be grandfathered, but new suites require development permits and inspections.

An illegal suite creates problems beyond tax: insurance may not cover a fire that occurs in an unregistered rental space, and tenants in illegal suites still have tenancy rights under provincial law.

Practical Record-Keeping for Basement Suite Landlords

CRA's 6-year retention rule applies to every receipt, statement, and record connected to your rental suite. For capital property items — the suite itself, major improvements — records must be kept for as long as you own the home plus six years after sale.

What to keep:

Your personal use calculation. Measure the floor plan, document your methodology, and keep it on file. This is your defence if CRA questions your deduction percentages.

Annual mortgage interest statement. From your lender, showing total interest paid each calendar year. Apply your rental % to arrive at your deductible amount.

Property tax notice. One document, one deduction — but keep it every year.

Insurance premium statements. Annual renewal documents showing the premium paid.

Utility bills or annual summaries. Many utility providers offer a year-to-date summary in December or January — download and keep it.

Every repair and maintenance invoice. Date, vendor, amount, description of work. Suite-specific repairs are 100% deductible; keep them clearly separated from whole-home repairs in your records.

Lease agreements. Keep every signed lease for as long as you own the property.

Rent payment records. A complete log of every payment received — date, amount, method. If a tenant ever claims non-payment or the CRA questions your gross income, your rent ledger is the evidence.

Filing Your T776: Step by Step

Your basement suite income and expenses go on Form T776 (Statement of Real Estate Rentals), filed with your T1 personal return. One T776 per rental property — since the suite is in your home, it's one T776 for the property.

Part 1: Your name, address of the rental property (your home address), and co-ownership percentage if applicable.

Part 2 (Income): Gross rents collected during the year. This is your total rent received — not what you expected, but what you actually collected.

Part 3 (Expenses): Each category on its own line, with your rental-portion amounts already calculated. The form has specific lines for each expense type — advertising, insurance, interest, maintenance, management fees, property taxes, utilities, and other.

Line 9949 (Personal portion): This is where you enter the personal-use adjustment — the portion of expenses that relate to your own living space, which you're not claiming. Most tax software calculates this automatically if you enter total expenses and your rental percentage.

Net income or loss: Gross rent minus deductible expenses. If your expenses exceed your rental income, you have a rental loss — which can generally be applied against your other income to reduce your overall tax payable. This is one of the legitimate benefits of renting a basement suite even in years where the income is modest.

The Numbers in Practice: A Quick Example

In this example, a homeowner collecting $18,000 in rent ($1,500/month) ends up with $6,390 in net taxable rental income after legitimate deductions. At a 33% combined federal/provincial marginal rate, the income tax owing is roughly $2,109 — not $5,940 as it would be without the deductions. The mortgage interest deduction alone saves over $2,000 in tax.

The Bottom Line

Basement suite rental income is taxable, but the deductions available — particularly mortgage interest — substantially reduce what you actually owe. The most important things to get right:

Declare the income. There is no minimum threshold. All rent collected is reportable.

Measure your suite and calculate your rental percentage accurately. This number is the multiplier for every shared expense deduction. Keep the calculation on file.

Claim mortgage interest correctly. Use your lender's annual statement, use Canadian semi-annual compounding math, and apply your rental percentage. This is your largest deduction.

Don't claim CCA. Unless you have a specific reason and have confirmed the capital gains math with an accountant, claiming Capital Cost Allowance on a basement suite costs far more in eventual capital gains tax than it saves in current-year deductions.

Keep everything for 6 years — longer for capital items like the suite itself and any major renovations.

This guide covers general information about CRA requirements for basement suite rental income as of 2026. Tax rules are complex and individual situations vary — always consult a CPA familiar with Canadian rental income and principal residence rules before filing.