Mortgage Approval 101: GDS & TDS Explained

Nicole Hayes • September 10, 2025

Can You Afford That Mortgage? Let’s Talk About Debt Service Ratios

One of the biggest factors lenders look at when deciding whether you qualify for a mortgage is something called your debt service ratios. It’s a financial check-up to make sure you can handle the payments—not just for your new home, but for everything else you owe as well.


If you’d rather skip the math and have someone walk through this with you, that’s what I’m here for. But if you like to understand how things work behind the scenes, keep reading. We’re going to break down what these ratios are, how to calculate them, and why they matter when it comes to getting approved.


What Are Debt Service Ratios?

Debt service ratios measure your ability to manage your financial obligations based on your income. There are two key ratios lenders care about:

  1. Gross Debt Service (GDS)
    This looks at the percentage of your income that would go toward housing expenses only.

   2.  Total Debt Service (TDS)
        This includes your housing costs plus all other debt payments—car loans, credit cards, student loans, support payments, etc.


How to Calculate GDS and TDS

Let’s break down the formulas.


GDS Formula:

(P + I + T + H + Condo Fees*) ÷ Gross Monthly Income


Where:

P = Principal

I = Interest

T = Property Taxes

H = Heat


Condo fees are usually calculated at 50% of the total amount


TDS Formula:

(GDS + Monthly Debt Payments) ÷ Gross Monthly Income


These ratios tell lenders if your budget is already stretched too thin—or if you’ve got room to safely take on a mortgage.


How High Is Too High?


Most lenders follow maximum thresholds, especially for insured (high-ratio) mortgages.

As of now, those limits are typically:

GDS: Max 39%

TDS: Max 44%


Go above those numbers and your application could be declined, regardless of how confident you feel about your ability to manage the payments.


Real-World Example

Let’s say you’re earning $90,000 a year, or $7,500 a month.

You find a home you love, and the monthly housing costs (mortgage payment, property tax, heat) total $1,700/month.


GDS = $1,700 ÷ $7,500 = 22.7%


You’re well under the 39% cap—so far, so good.


Now factor in your other monthly obligations:

  • Car loan: $300
  • Child support: $500
  • Credit card/line of credit payments: $700
    Total other debt = $1,500/month


Now add that to the $1,700 in housing costs:
TDS = $3,200 ÷ $7,500 = 42.7%


Uh oh. Even though your GDS looks great, your TDS is just over the 42% limit. That could put your mortgage approval at risk—even if you’re paying similar or higher rent now.


What Can You Do?

In cases like this, small adjustments can make a big difference:

  • Consolidate or restructure your debts to lower monthly payments
  • Reallocate part of your down payment to reduce high-interest debt
  • Add a co-applicant to increase qualifying income
  • Wait and build savings or credit strength before applying


This is where working with an experienced mortgage professional pays off. We can look at your entire financial picture and help you make strategic moves to qualify confidently.


Don’t Leave It to Chance

Everyone’s situation is different, and debt service ratios aren’t something you want to guess at. The earlier you start the conversation, the more time you’ll have to improve your numbers and boost your chances of approval.


If you're wondering how much home you can afford—or want help analyzing your own GDS and TDS—let’s connect. I’d be happy to walk through your numbers and help you build a solid mortgage strategy.


Nicole Hayes
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By Nicole Hayes • September 30, 2026
Why the Source of Your Down Payment Matters More Than You Think When buying a home, most people focus on how much they need for a down payment. What often gets overlooked is that where the down payment comes from matters just as much to the lender . The source of your down payment affects approval, risk assessment, and how your mortgage is structured. Here’s why lenders care—and what you need to know. 1. Anti–Money Laundering Requirements Lenders aren’t just being cautious—they’re legally required to verify the source of your down payment. To comply with anti–money laundering regulations, lenders must document where every dollar of the down payment came from on every purchase. Acceptable Down Payment Sources Down payments can come from: Your own savings or investments Borrowed funds through an insured program (such as FlexDown) A gift from an immediate family member How You Prove the Source Personal savings: You’ll need bank statements showing the funds have been in your account for at least 90 days , or proof they were accumulated through payroll deposits or other acceptable sources. Borrowed funds: Any borrowed portion must be included in your debt service ratios , since you’re responsible for repayment. Gifted funds: A signed gift letter is required confirming the money is a true gift with no repayment obligation , along with proof the funds were deposited into your account. 2. Financial Suitability and Risk The source of your down payment also tells the lender a lot about your financial habits. Down payments coming from your own savings demonstrate: Positive cash flow The ability to save consistently Strong financial management This reassures lenders that you’re more likely to keep up with mortgage payments. If the down payment is borrowed or gifted, lenders may look more closely at the rest of your application to ensure the mortgage remains affordable. Why a Larger Down Payment Helps From a lender’s perspective, more equity equals lower risk. The more money you have invested in the property, the less likely you are to walk away from the mortgage. This reduces the lender’s exposure and can sometimes result in better terms. 3. Down Payment and Loan-to-Value (LTV) Your down payment directly establishes your loan-to-value ratio (LTV)—the percentage of the property’s value being financed. In Canada: Lenders can finance up to 95% of a property’s value The buyer must contribute at least 5% as a down payment Example: On a $400,000 purchase: Maximum mortgage = $380,000 Minimum down payment = $20,000 How the Source Affects LTV Property value must be genuine and independently supported. Lenders rely on appraisals and comparable sales—not artificial price inflation. If: The seller provides money back The buyer doesn’t bring the full down payment independently Funds move “behind the scenes” …the lender considers this a change to the LTV and may decline the mortgage. All financial details of the purchase must be fully disclosed. Non-disclosure is mortgage fraud , and lenders will not proceed if the numbers don’t align. Final Thoughts Lenders ask for detailed documentation about your down payment source for good reason—it affects legality, risk, and the structure of your mortgage. Understanding these rules upfront helps avoid delays, declined applications, and last-minute surprises. If you’d like to review your down payment options or talk through mortgage financing, feel free to connect anytime. I’d be happy to walk you through the process and help you plan with confidence.
By Nicole Hayes • September 23, 2026
Mortgage Options During Divorce or Separation: What You Should Know If you’re going through—or considering—a divorce or separation, you may not realize that there are mortgage solutions specifically designed to help one party keep the home . For many people, the family home is their largest asset and where most of their equity is tied up. In situations like this, a spousal buyout program can allow one person to refinance the property and buy out the other party’s share—often up to 95% of the home’s value . This option can work whether you want to keep the home or your former partner does. What Is the Spousal Buyout Program? The spousal buyout program is a refinancing option that allows one owner to purchase the other owner’s share of the property as part of a separation or divorce settlement. In some cases, it can also be used to pay off jointly held debts, as outlined in a legal agreement. Below are some of the most common questions about how the program works. Is a finalized separation agreement required? Yes. Lenders require a signed and finalized separation agreement that clearly outlines how assets and debts are to be divided. This document is essential for approval. Can the funds be used for renovations or personal debts? No. Funds from a spousal buyout can only be used to: Buy out the other owner’s share of equity Pay off joint debts specifically listed in the separation agreement They cannot be used for renovations, personal loans, or unrelated expenses. How much equity can be accessed? The maximum amount available is the amount required to: Buy out the other party’s agreed-upon share of equity Pay off any joint debts listed in the agreement This amount cannot exceed 95% loan-to-value . What is the maximum loan-to-value allowed? The maximum loan-to-value is the lesser of : 95%, or The remaining mortgage balance plus the required buyout and joint debt payout The property must be the primary owner-occupied residence . Do all parties need to be on title? Yes. All individuals involved in the buyout must currently be registered on title. Your solicitor will confirm this through a title search. Does this only apply to married or common-law couples? No. While commonly used for married or common-law couples, the program may also apply to siblings or friends who jointly own a property and need one party to exit the mortgage. These cases are typically reviewed on an exception basis and require insurer approval. If no separation agreement exists, the purchase contract must clearly outline the buyout terms. Is a full appraisal required? Yes. A physical, on-site appraisal is required to confirm the property’s value before the mortgage can be finalized. Final Thoughts This overview covers some of the most common questions about mortgage options during separation or divorce, but every situation is different. Working with an independent mortgage professional gives you access to multiple lenders, specialized programs, and unbiased advice—so you can clearly understand your options and choose what’s best for your future. If you’re navigating a separation and need guidance around keeping or selling the home, feel free to connect anytime. All conversations are handled with discretion and confidentiality, and I’d be happy to walk you through your options.