How to Qualify for a Mortgage in Ontario: What Lenders Actually Look At

Mortgage Qualification Is Not a Mystery

Most people treat mortgage qualification like a black box. You hand over documents, wait a few days, and someone tells you yes or no. That is a bad way to approach the largest loan you will ever take on.

Lenders follow a formula. The inputs are specific, the thresholds are published, and the math is straightforward once you know the variables. This article breaks down what Ontario lenders evaluate, how each factor affects your borrowing power, and where people actually get tripped up. Rules referenced here reflect OSFI Guideline B-203 and CMHC requirements2 as of April 2026, with the Bank of Canada overnight rate at 2.25%1 and the benchmark qualifying rate at 5.25%.

Credit Scores: What You Need vs. What You Think You Need

There is a persistent myth that you need a 750+ credit score to get a mortgage. You do not. A 680 gets you access to every A-lender in the country and the best available rates. Above 680, your score barely moves the needle. Below 680 is where things get more expensive, and below 600 is where doors start closing.

A few things most people get wrong about credit scores and mortgages:

• Both scores matter. Equifax and TransUnion can differ by 50 points or more. Lenders typically pull both and use the lower of the two. Check both before you apply.
• Utilization counts more than you think. Carrying balances above 30% of your credit limits drags your score down, even if you pay on time. Pay down revolving balances before applying.
• A single late payment is not fatal. One 30-day late from two years ago will not disqualify you at an A-lender. A pattern of lates, or anything that went to collections, is a different story.
• No credit is almost as bad as bad credit. If you have never had a credit card, car loan, or line of credit, lenders have nothing to assess. You need at least two active trade lines with 12+ months of history.

GDS and TDS Ratios: The Math That Decides Your Limit

Your credit score determines whether a lender will work with you. Your debt service ratios determine how much they will lend you. These are the two numbers that set your ceiling.

Gross Debt Service (GDS) Ratio

GDS measures your housing costs as a percentage of your gross (pre-tax) income. Housing costs include:

• Mortgage payment (calculated at the stress test rate, not your actual rate)
• Property taxes
• Heating costs (lenders use a standard estimate, typically $100 to $150/month)
• 50% of condo fees, if applicable

Maximum GDS: 39% for most insured mortgages.2 Some lenders allow up to 32% to 35% for conventional (uninsured) mortgages with weaker files.

Total Debt Service (TDS) Ratio

TDS takes your GDS costs and adds all other monthly debt obligations: car payments, student loans, credit card minimums, lines of credit, child support, and any other recurring debt.

Maximum TDS: 44% for insured mortgages.2 Again, some lenders cap this lower for uninsured deals or borrowers with other risk factors.

What This Looks Like in Practice

Say your household gross income is $120,000 per year, or $10,000 per month.

• GDS at 39%: Your total housing cost cannot exceed $3,900/month at the stress test rate.
• TDS at 44%: Your housing cost plus all other debts cannot exceed $4,400/month.
• If you have a $500/month car payment and $200/month in student loan payments, that leaves only $3,700/month for housing under TDS, which is now the binding constraint.

This is why paying off a car loan before applying for a mortgage can increase your purchasing power by $40,000 to $60,000. The math is direct.

The Stress Test: How It Actually Works

Under OSFI Guideline B-20,3 every borrower at a federally regulated lender must qualify at the higher of 5.25% or their contract rate plus 2%. This is called the mortgage qualifying rate, or stress test.

With the Bank of Canada overnight rate at 2.25%1 as of April 2026, typical 5-year fixed rates for well-qualified borrowers sit around 3.8% to 4.3%. Add 2% and you get 5.8% to 6.3%, which is above the 5.25% floor. So most borrowers today are qualifying at their contract rate plus 2%.

The practical effect: the stress test reduces your maximum purchase price by roughly 20%. A household that could carry an $800,000 mortgage at 4% might only qualify for $640,000 to $660,000 under the test.

Some stress test realities worth knowing:

• It applies to purchases and refinances. Even if you already own the home, the stress test applies when refinancing.
• Switching lenders at renewal triggers it. Stay with your current lender and there is no new stress test. Move to a different lender for a better rate and you must re-qualify. This traps some borrowers with their existing lender.
• Some credit unions are exempt. Provincially regulated credit unions are not bound by OSFI rules. However, most apply the stress test voluntarily, and their rates are not always competitive enough to offset the difference.

A Real-World Scenario

A dual-income couple in Hamilton earns a combined $140,000/year. They have $60,000 saved and carry a $350/month car loan. Their offered rate is 4.1%.

• Stress test rate: 4.1% + 2% = 6.1%
• TDS limit at 44%: $5,133/month total debt capacity
• Less car payment: $5,133 - $350 = $4,783 available for housing
• At 6.1% over 25 years, that supports a mortgage of roughly $685,000 (after property tax and heating estimates)
• With $60,000 down, maximum purchase price: approximately $745,000

If they pay off the car loan first, their housing budget jumps to $5,133/month, pushing their max above $800,000. One debt elimination added over $55,000 in buying power.

Income Verification: Salaried, Self-Employed, and Everyone Else

Lenders need to confirm that the income you claim is real, stable, and likely to continue. How they verify it depends entirely on how you earn it.

Salaried Employees

This is the simplest case. Lenders want:

• A recent pay stub (within 30 days)
• An employment letter confirming your position, salary, start date, and that the role is permanent
• Your most recent T4 and Notice of Assessment (NOA) from CRA

If you recently switched jobs, expect questions. Lenders prefer at least 3 months in the new role. Moving from salaried to contract or commission creates a separate set of requirements.

Commission and Bonus Income

Lenders will use your commission or bonus income, but only if you have a 2-year track record. They take the 2-year average. If your commission income was $40,000 last year and $60,000 the year before, the lender uses $50,000. If the trend is declining, some lenders use the lower figure.

Self-Employed Borrowers

This is where qualification gets complicated, and where the gap between reality and what shows on paper causes the most friction.

For a self-employed borrower filing T1 Generals, the lender uses your line 15000 income (net business income after expenses), averaged over two years. The problem: if you aggressively write off expenses to reduce your tax bill, your declared income may be far lower than what you actually take home.

Options for self-employed borrowers with low declared income:

• Stated-income programs (B-lenders): Some lenders accept a reasonable income estimate supported by bank statements or financial statements. Expect 10% to 20% down and rates 0.5% to 1.5% above A-lender pricing.
• Larger down payment: At 35% down, lenders become significantly more flexible on income documentation.
• Adjust your tax strategy: If you plan to buy within 1 to 2 years, talk to your accountant about declaring more income now. The extra tax cost may be far less than the rate premium on a B-lender mortgage.

Gig Workers and Non-Traditional Income

Freelancers and contract workers face the same verification challenge as the self-employed: lenders want T1 Generals and NOAs for at least 2 years. If gig income supplements a salaried job, it can be added on top, but only with documentation. Rental income from an existing property can also boost your qualifying amount, though lenders add the property's carrying costs to your debt obligations.

Down Payment Tiers and What Changes at Each Level

The size of your down payment does not just affect your monthly payment. It changes the rules of the entire deal.2

What catches buyers off guard:

• Insured mortgages often have lower rates than uninsured ones. Because the insurer guarantees the loan, the lender's risk is near zero. Many lenders offer their best rates on insured mortgages. Putting exactly 20% down can sometimes mean a higher rate than putting 15% down.
• The insurance premium is not trivial. On a $600,000 purchase with 5% down ($30,000), the insurance premium is 4% of $570,000 = $22,800. That gets rolled into your mortgage, and you pay interest on it for the full amortization.
• Source of down payment matters. Lenders trace where your funds came from. Savings, RRSP withdrawals, FHSAs, gifts from immediate family (with a gift letter), and sale proceeds are all acceptable. An unexplained large deposit will trigger questions and delay your approval.

Common Disqualifiers and How to Fix Them

Most mortgage declines are not permanent. They are timing problems or documentation problems. Here are the ones that come up repeatedly and what to do about each.

High Debt Ratios

If your TDS exceeds 44%, you have two levers: increase income or reduce debt. Paying off a credit card, closing a car loan, or consolidating high-interest debt can bring your ratios into range within weeks.

Insufficient Down Payment Documentation

Lenders require a 90-day history for your down payment funds. If money appeared in your account recently without a paper trail, you need to document the source: bank statements, gift letters, sale receipts, or TFSA/FHSA withdrawal confirmations. Start organizing these well before you apply.

Employment Gaps or Recent Job Changes

A 3-month gap in employment from a year ago is usually fine with documentation. A job change last week is a problem. If you are planning a career move, get your mortgage approval locked in first. If you have already switched, most A-lenders want to see you past your probationary period.

Property Issues

Not every property qualifies for every mortgage type. Lenders and insurers have restrictions on condos in buildings with litigation or reserve fund shortfalls, properties with environmental concerns (former gas stations, oil tanks), rural properties on well and septic (which may require additional inspections), and mixed-use properties with commercial units. If the property has issues, ask your broker before making an offer.

Consumer Proposals and Bankruptcies

A consumer proposal does not permanently bar you from getting a mortgage. Most A-lenders want the proposal fully paid and discharged for at least 2 years, with re-established credit. B-lenders may work with you sooner at higher rates. A bankruptcy typically requires 2+ years post-discharge for B-lender consideration and 3+ years for an A-lender.