Total Debt Service (TDS)

Total Debt Service (TDS) starts with the same qualifying housing costs as GDS and then adds the monthly obligations assigned to the borrower's other debts.

TDS = qualifying housing costs + other qualifying monthly debt payments, divided by gross qualifying income × 100.

The formula must use the same time units. Monthly costs go over monthly qualifying income; annual costs can be converted consistently.

Three upstream choices determine TDS: what income is accepted, what rental surplus/shortfall is produced, and what payment is assigned to every liability. A change in any one can move the ratio.

That is why the three prerequisite pages in this hub matter: Income, Rental Income and Liabilities.

Continue the GDS example: qualifying income is $12,500 per month and subject-property housing costs are $4,400, giving 35.2% GDS.

Now add a $650 car payment, $300 qualifying credit-card payment and $450 line-of-credit obligation. Total qualifying outflow becomes $5,800 per month. $5,800 ÷ $12,500 = 46.4% TDS.

The borrower passes a 39% insured GDS ceiling but exceeds the standard 44% insured TDS ceiling. The binding problem is therefore the total debt load, not the housing cost.

For mortgages that must satisfy the federal insured/insurable eligibility framework, GDS must not exceed 39% and TDS must not exceed 44%. This is a Canadian eligibility boundary, not a discretionary ratio published by one insurer.

The lender and insurer can still differ on how income, rent, debts and other inputs are calculated. But once those inputs are established, a lender cannot use an ordinary conventional ratio exception to turn a 46% TDS insured file into a 44% file.

A conventional uninsured file is different. The lender can apply its own ratio policy and exception authority, so TDS can sometimes be considered above 44% when the rest of the file is strong enough—credit, equity, income stability, liquidity, property quality and the size/reason for the exception all matter.

HopeWell treats the ratio as one constraint inside the whole file, not as a stand-alone score. The practical question is whether the higher ratio is being offset by genuine strengths or merely hiding an affordability problem.

A 50/50 GDS/TDS structure is common in parts of the alternative channel, but product-specific public material shows why one ceiling should never be applied to the entire category. Equitable Bank's current alternative business-for-self material publishes 50%/50% as standard and 60%/60% in select markets, subject to its credit and other product requirements.

Home Trust publicly shows a funded borrower example at 60% TDS; that example demonstrates capability in one file, not a universal Home Trust maximum. B2B Bank's current Net Worth Program publishes 70% TDS with higher TDS potentially considered by exception, again for that specific product rather than for every B2B mortgage.

HopeWell's broader broker-channel experience is consistent with the idea that alternative lenders can tolerate higher ratios than a standard insured file. But the ratio is only one control: credit, equity, property, income reasonableness, pricing, lender fees and the borrower's actual cash-flow comfort still matter.

Private residential lending is often driven more by equity, property, loan purpose and exit than by a bank-style 39/44 ratio. There is no universal private-lender GDS/TDS ceiling.

That does not mean affordability can be ignored. Ontario mortgage suitability obligations still require the borrower's circumstances, ability to carry the proposed payment and the risks of the structure to be considered. In practice, private lenders and brokers may review bank statements or cash flow even where they do not calculate formal GDS/TDS in the same way as an insurer.

TDS improves when one or more of the real inputs improve: accepted income rises, recognized rental economics improve, qualifying debt payments fall, housing cost falls, or the requested mortgage decreases.

Changing lenders can help only where another lender has a legitimate different methodology or exception policy. It cannot make an undisclosed debt disappear or justify inflating income.

TDS uses gross qualifying income and a defined list of obligations. It does not fully capture taxes, food, childcare, commuting, home maintenance, insurance, savings goals or lifestyle expenses.

A borrower approved at a high ratio needs a separate cash-flow stress test. A mortgage can be credit-policy acceptable and still be personally uncomfortable.

Use the Maximum Mortgage Calculator to enter GDS/TDS limits, taxes, heat and monthly liabilities. Use the Mortgage Affordability Calculator for a broader affordability view.

If the ratio is high, return to How Lenders Calculate Liabilities and identify which payment contributes most to the numerator.