Debt Service Ratio BC: GDS & TDS Mortgage Approval Limits

If you are buying a condo or any strata property, there is a fifth piece. Lenders add 50 percent of your monthly strata fees to the housing costs. So a $400 strata fee adds $200 to the GDS calculation, not the full amount. That half-fee rule catches a lot of condo buyers off guard, because a building with high fees can quietly push the ratio over the line.

The full GDS picture for a strata home is therefore principal, interest, property taxes, heat, and half of the strata fee, all divided by gross income. For a freehold house, drop the strata piece.

The TDS formula and what gets added

Total debt service starts with everything in GDS and adds the rest of your monthly debt obligations. That includes car loans and leases, student loan payments, lines of credit, the minimum payment on every credit card, and any support payments you are required to make.

Credit cards are the part people misjudge. Lenders do not use what you actually pay each month. They use the minimum payment, which is usually around 3 percent of the balance. A $10,000 card balance can add roughly $300 a month to your TDS even if you pay it in full every cycle. A car payment of $500 a month sits in TDS at the full amount.

This is why two buyers with identical incomes and identical target homes can get different answers. The one carrying a car loan and a student line of credit has a much higher TDS, and that ratio, not the home itself, is what trips the approval.

The number you plug in is not your contract rate

Here is the part that surprises almost everyone. The mortgage payment used inside the GDS and TDS math is not calculated at the rate your lender quotes you. It is calculated at the federal stress-test rate, which is the higher of your contract rate plus 2 percent or 5.25 percent.

So if a lender offers you 4.5 percent, your ratios are run at 6.5 percent. The payment is bigger, the ratios are higher, and you qualify for less than the contract rate alone would suggest. This applies to insured and uninsured mortgages alike. Every worked example below uses a 6.5 percent qualifying rate for exactly this reason. If you want the mechanics of the stress test on its own, read our guide on the mortgage stress test in Canada.

Worked example: a Surrey condo where TDS is the ceiling

Surrey condos are sitting at a median of $508,000 right now across the city. Take a couple buying at that price with 20 percent down, leaving a mortgage of $406,400. At the 6.5 percent qualifying rate over 25 years, the principal and interest come to about $2,722 a month.

Now add the rest of the housing costs. Say property tax is $2,000 a year, which is about $167 a month, heat is $100 a month, and the strata fee is $400 a month. The lender counts half the strata fee, so $200. Total monthly housing cost is roughly $3,189, or about $38,266 a year.

• GDS at $100,000 income: $38,266 divided by $100,000 is 38.3 percent. Just under the 39 percent limit, so GDS passes.

So far so good. But this couple also has a $400 car payment and a credit card with a $150 minimum, which is $550 a month in other debt. Add that in.

• TDS at $100,000 income: housing of $38,266 plus other debt of $6,600 is $44,866 a year. Divided by $100,000 that is 44.9 percent. Over the 44 percent limit, so the file is declined.

The home is affordable on GDS. The car loan is what breaks it. Paying off or paying down that car loan, or earning about $2,000 more in qualifying income, brings TDS back under 44 percent and the approval through. This is the single most common reason a BC buyer who feels like they can afford a place gets turned down.

Worked example: a Metro Vancouver condo that clears both

Now a cleaner case. The median Metro Vancouver condo is $649,900. A buyer puts 20 percent down for a $519,920 mortgage. At 6.5 percent over 25 years, principal and interest are about $3,483 a month.

Add property tax of $1,800 a year, or $150 a month, heat of $100, and a $450 strata fee counted at half, so $225. Monthly housing cost is about $3,958, or roughly $47,491 a year. This buyer earns $135,000 and carries no other debt.

• GDS: $47,491 divided by $135,000 is 35.2 percent. Under 39 percent.
• TDS: with no other debt, TDS equals GDS at 35.2 percent. Under 44 percent.

Both ratios clear comfortably, with room to spare for the lender. The contrast with the Surrey example is the whole lesson. A higher purchase price is not what sinks an application. Carried debt and the income behind it are.

Where lender flexibility comes in

The 39 and 44 percent figures are the guidelines for an insured mortgage, the kind backed by CMHC or another mortgage insurer when your down payment is under 20 percent. They are also the benchmark most lenders apply to uninsured files.

That said, the limits are not always hard walls. A borrower with a strong credit score, a large down payment, and stable income can sometimes be approved above 39 percent GDS, with TDS stretching toward the high 40s on an uninsured mortgage. The flexibility runs the other way too. Weaker credit or unstable income can push a lender to apply tighter internal limits than the published guideline. Treat 39 and 44 as the planning numbers, and know that your real ceiling depends on the full strength of your file.

How to run your own numbers before you apply

You can estimate your ratios in a few minutes. Start with the price range you are considering and pull realistic figures.

• Estimate the payment at 6.5 percent, not the rate you hope to get. Every property page on Zealty has a built-in payment estimator, and if you want a rate before you shop you can get free mortgage advice from a Zealty expert.
• Add property tax and heat. Property tax data shows on every listing, and you can check current numbers on the Metro Vancouver housing market page.
• Add half the strata fee if it is a condo or townhouse. The full fee shows on the listing detail.
• List every other debt payment, using the minimum payment on credit cards and the full amount on loans and leases.
• Divide by your gross household income for the year. Housing alone gives GDS. Housing plus other debt gives TDS.

If your TDS lands above 44 percent, the fastest fixes are usually paying down a car loan or a credit card balance, increasing your down payment to lower the mortgage, or adding a co-applicant whose income lifts the denominator. Each one moves the ratio in your favour.

Bottom line

GDS and TDS are the real gatekeepers of a mortgage in British Columbia. GDS caps your housing costs at 39 percent of gross income, TDS caps housing plus all other debt at 44 percent, and both are calculated at the stress-test rate rather than your contract rate. For most BC buyers the TDS ceiling is what binds, and the debt you already carry matters as much as the home you want to buy. Run both numbers before you shop so you know your true price range, not the one your salary alone suggests.

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