Financing a Rental in Ontario: How Much You Put Down, and How Lenders Actually Count the Rent
The rent covers the mortgage, so the bank will approve you — right? That assumption is the most expensive one in investment-property financing. Whether a lender adds the rent to your income or offsets it against the cost can decide the whole deal.
How do lenders count rental income toward a mortgage — and why can a cash-flow-positive rental still get declined?
A lender does not approve you on whether the rent covers the mortgage — it approves you on whether your file fits two ratios, GDS and TDS, after the rent has been discounted. That is why a cash-flow-positive rental can still be declined. For a non-owner-occupied rental (2-4 units) financed through CMHC’s Income Property insurance product, those ratios sit at 39% and 44%, the minimum down payment is 20% (an 80% loan-to-value ceiling), and the insured value must be under $1,000,000. As for the rent, CMHC allows two routes: adding a slice of the gross rent (up to 50%) to your income — the add-back method — or a net-rental-income calculation left to each lender’s own guidelines, the offset method. Which route a lender takes, and how generous it is, is what this piece unpacks.
Source: CMHC Income Property insurance product page (20% down / 80% LTV; up to 50% of gross rent included; net-rental method; GDS 39% / TDS 44%; insured value under $1,000,000); OSFI Minimum Qualifying Rate for uninsured mortgages. Reviewed 2026-08-11.
I’m Arthur Zhao. The rental that gets declined is almost never the one that looked shaky on paper — it is usually the one the buyer had already penciled out as a sure thing, rent running comfortably above the mortgage, money left over every month.
The reason that math does not carry over to the lender is the whole point of this piece: a lender does not approve you on “rent minus mortgage.” It runs your rent through its own rules and drops the result into two ratios you have probably never been asked about. Rental financing parts ways with financing your own home at nearly every step — from how much you put down to how the lender counts the rent you collect. Below are the two that decide the most: why the down-payment floor sits at 20% or more, and how a lender turns your rent into a number on the file — add-back versus offset, and why the same property can clear one way and stall the other.
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Covering the mortgage is not the test the bank runs
Most buyers frame a rental as simple arithmetic: rent of $2,100, mortgage of $1,850, “I’m up $250 a month — solid.” The instinct is that the bank sees it the same way.
It does not. A lender never underwrites “rent minus mortgage.” It takes your rent, discounts it by its own rules, and drops the result into two ratios that measure whether you can carry the debt. Those ratios are GDS (gross debt service) and TDS (total debt service) — CMHC’s Income Property product sets them at 39% and 44%. Your “positive cash flow” and the lender’s “does it fit the ratios” are two entirely different ledgers.
Your own home vs an investment property
Why the rent you count and the rent the lender counts differ
Here is the single most useful thing to internalize: you count the full rent; the lender counts a discounted version of it. There are two mainstream ways a lender does that discounting, and the cleanest way to keep them straight is by where each one lands: one adjusts your income, the other adjusts your debt load. CMHC’s own product spells out both — a gross-rent inclusion of up to 50%, and a net-rental-income method left to lender guidelines. The next card lines them up side by side.
Rental add-back vs rental offset
⚠️Offset ratios are lender policy, not a national rule. Different lenders can credit the same rent very differently, which is why one rental can be approved at one bank and declined at another on the same numbers. Do not treat any single lender’s ratio as “the rule” — the real figure comes from how a lender assesses your specific file.
A quick illustration
Take some hypothetical numbers (to show the mechanics, not market rates): a duplex where each side rents for roughly $2,000, and the monthly carrying cost — mortgage, property tax, insurance — runs, say, about $2,500.
• Add-back: the lender takes a portion of the gross rent (CMHC allows up to 50%) and adds it to your monthly income, then runs your ratios on that higher income. Here the rent is a boost to income.
• Offset: the lender applies its own ratio to shave part of the rent off that $2,500 carrying cost, and only the leftover shortfall counts against you. Here the rent is a hedge against the debt.
Which one helps you more depends on two things: the ratio the lender uses, and how high the rent is relative to the carrying cost. When rent is strong and the lender’s offset is generous, offset tends to win; otherwise the two can land close. The point is that you do not get to pick — the lender’s policy does.
The stress test has not gone away
Even after the rent is counted, one national gate remains: the stress test. For uninsured mortgages (20%+ down, where most rentals land), OSFI’s Minimum Qualifying Rate is the greater of your contract rate plus 2% or 5.25%. The lender must confirm you can carry the payment at that higher rate, not the rate you actually get — and having rental income does not exempt you from it.
One 2024 change is worth filing away: since 2024-11-21, OSFI no longer expects lenders to apply the MQR to an uninsured straight switch at renewal — moving your existing mortgage to a new lender with no new money and no longer amortization. A pure lender switch on the same terms may now clear without the stress test; a new purchase, more money, or a longer amortization still has to pass it.
ℹ️A note on the stress test. The 5.25% floor and the “contract rate + 2%” formula come from OSFI (verified 2026-08-11). Regulatory numbers change; when it is your turn to borrow, confirm the current figure with the lender. Most rentals are financed as uninsured mortgages, so this gate is rarely one you can skip.
💡 My take: whether a rental gets financed usually hinges less on “is this property cash-flow positive” and more on “which method the lender uses, and how much of the rent it credits.” The same property you pencilled out as a sure thing can miss TDS by a hair in a stricter lender’s hands. So do not wait until you have found the place and signed an offer to ask about financing — take your income, existing debts, and target property to a licensed mortgage broker first, get the “which method, how much” answer, and then go negotiate. Reversing that order is the costly mistake.
When you are not sure, who to ask
This piece is the framework: 20% down or more, rent counted by add-back or offset, and an MQR gate on top. But every number that actually lands on your file — how much you can borrow, which method applies, what ratio you get — moves with the lender and with your own situation.
So the practical move is to treat this as the map and hand the route to a licensed mortgage broker or lender. They can run your real income, existing debts, and target property through an actual underwriting lens. This is general information, not mortgage or legal advice for your circumstances; your approval rests on a licensed broker or lender assessing your file.
- CMHC Income Property insurance product — non-owner-occupied 2-4 units, 20% minimum down / 80% LTV; up to 50% of gross rent included; net-rental method per lender guidelines; GDS 39% / TDS 44%; insured value under $1,000,000; 25-year maximum amortization
- OSFI Minimum Qualifying Rate for uninsured mortgages — the greater of the contract rate plus 2% or 5.25%
- OSFI — uninsured straight switches exempted from the prescribed MQR effective 2024-11-21, with portfolio LTI limits
- Department of Finance Canada — 2024 mortgage reforms: insured price cap raised to $1,500,000 effective 2024-12-15 (owner-occupied stream, not the investment product)
📘Complete GuideMortgage Guide: Ontario Start to Finish →
Buying a Rental Property Through a Corporation vs Your Personal Name in Ontario: The Real Trade-Offs →Investment Property Cashflow Before Buying →What Is a Cap Rate? The One Number to Understand Before Buying a GTA Rental →Ontario Mortgage Guide →
Frequently Asked Questions
The rent covers the mortgage, so why won’t the bank just approve me?
Because the lender never underwrites “rent minus mortgage.” It discounts your rent by its own rules and drops the result into your GDS and TDS ratios (CMHC’s Income Property product sets these at 39% and 44%). A property that is cash-flow positive to you can still miss those ratios, especially once the stress test applies.
How much of the rent will a lender actually count?
Not all of it. Under CMHC’s add-back approach, up to 50% of gross rent can be included as income; the alternative net-rental-income (offset) method is left to each lender’s own guidelines. So the rent you collect and the rent the lender credits are two different numbers (source: CMHC Income Property, reviewed 2026-08-11).
Do I really need 20% down for a rental in Ontario?
For a non-owner-occupied rental financed through CMHC’s Income Property product, yes — the minimum is 20% (an 80% LTV ceiling), and the insured value must be under $1,000,000. The 5%/10% low-down-payment tiers apply to owner-occupied homes, not to investment rentals.
Does the mortgage stress test apply to investment properties?
Yes. Most rentals are financed as uninsured mortgages, so OSFI’s MQR applies: you qualify at the greater of your contract rate plus 2% or 5.25%. The one carve-out is a straight switch at renewal — since 2024-11-21, moving an uninsured mortgage to a new lender with no new money and no longer amortization no longer requires the MQR.
Can rent from a property I already own help me qualify for the next one?
Usually yes, but it is still discounted and still runs through your overall GDS/TDS and the stress test. The net or added-back rent from your existing rental feeds into the calculation, but how much counts and which method applies depends on the lender — do not assume owning one rental guarantees the next.
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