Mortgage Approval 101: GDS & TDS Explained

Dean Garrett • October 23, 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.


A man wearing a black shirt is smiling for the camera
Dean Garrett

Mortgage Professional

Your Guide to Real Estate Investment in Canada

By Dean Garrett • February 19, 2026
Your Guide to Real Estate Investment in Canada Real estate has long been one of the most popular ways Canadians build wealth. Whether you’re purchasing your first rental property or expanding an existing portfolio, understanding how real estate investment works in Canada—and how it’s financed—is key to making smart decisions. This guide walks through the fundamentals you need to know before getting started. Why Canadians Invest in Real Estate Real estate offers several potential benefits as an investment: Long-term appreciation of property value Rental income that can support cash flow Leverage , allowing you to invest using borrowed funds Tangible asset with intrinsic value Portfolio diversification beyond stocks and bonds When structured properly, real estate can support both income and long-term net worth growth. Types of Real Estate Investments Investors typically focus on one or more of the following: Long-term residential rentals Short-term or vacation rentals (subject to local regulations) Multi-unit residential properties Pre-construction or assignment purchases Value-add properties that require renovations Each type comes with different financing rules, risks, and return profiles. Down Payment Requirements for Investment Properties In Canada, investment properties generally require higher down payments than owner-occupied homes. Typical minimums include: 20% down payment for most rental properties Higher down payments may be required depending on: Number of units Property type Borrower profile Lender guidelines Down payment source, income stability, and credit history all play a role in approval. How Rental Income Is Used to Qualify Lenders don’t always count 100% of rental income. Depending on the lender and mortgage product, they may: Use a rental income offset , or Include a percentage of rental income toward qualification Understanding how income is treated can significantly impact borrowing power. Financing Options for Investors Investment financing can include: Conventional mortgages Insured or insurable options (in limited scenarios) Alternative or broker-only lenders Refinancing equity from existing properties Purchase plus improvements for value-add projects Access to multiple lenders is often crucial for investors as portfolios grow. Key Costs Investors Should Plan For Beyond the purchase price, investors should budget for: Property taxes Insurance Maintenance and repairs Vacancy periods Property management fees (if applicable) Legal and closing costs A realistic cash-flow analysis is essential before buying. Risk Considerations Like any investment, real estate carries risk. Key factors to consider include: Interest rate changes Market fluctuations Tenant turnover Regulatory changes Liquidity (real estate is not easily sold quickly) A strong financing structure can help manage many of these risks. The Role of a Mortgage Professional Investment mortgages are rarely “one-size-fits-all.” Lender policies vary widely, especially as you acquire more properties. Working with an independent mortgage professional allows you to: Compare multiple lender strategies Structure financing for long-term growth Preserve flexibility as your portfolio evolves Avoid costly mistakes early on Final Thoughts Real estate investment in Canada can be a powerful wealth-building tool when approached with a clear strategy and proper financing. Whether you’re exploring your first rental property or planning your next acquisition, understanding the numbers—and the lending landscape—matters. If you’d like to discuss investment property financing, run the numbers, or explore your options, feel free to connect. A well-planned mortgage strategy can make all the difference in long-term success.

Is Refinancing Your Mortgage a Good Way to Consolidate Debt?

By Dean Garrett • February 12, 2026
If you're a homeowner juggling multiple debts, you're not alone. Credit cards, car loans, lines of credit—it can feel like you’re paying out in every direction with no end in sight. But what if there was a smarter way to handle it? Good news: there is. And it starts with your home. Use the Equity You’ve Built to Lighten the Load Every mortgage payment you make, every bit your home appreciates—you're building equity. And that equity can be a powerful financial tool. Instead of letting high-interest debts drain your income, you can leverage your home’s equity to combine and simplify what you owe into one manageable, lower-interest payment. What Does That Look Like? This strategy is called debt consolidation , and there are a few ways to do it: Refinance your existing mortgage Access a Home Equity Line of Credit (HELOC) Take out a second mortgage Each option has its own pros and cons, and the right one depends on your situation. That’s where I come in—we’ll look at the numbers together and choose the best path forward. What Can You Consolidate? You can roll most types of consumer debt into your mortgage, including: Credit cards Personal loans Payday loans Car loans Unsecured lines of credit Student loans These types of debts often come with sky-high interest rates. When you consolidate them into a mortgage—secured by your home—you can typically access much lower rates, freeing up cash flow and reducing financial stress. Why This Works Debt consolidation through your mortgage offers: Lower interest rates (often significantly lower than credit cards or payday loans) One simple monthly payment Potential for faster repayment Improved cash flow And if your mortgage allows prepayment privileges—like lump-sum payments or increased monthly payments—those features can help you pay everything off even faster. Smart Strategy, Not Just a Quick Fix This isn’t just about lowering your monthly bills (although that’s a major perk). It’s about restructuring your finances in a way that’s sustainable, efficient, and empowering. Instead of feeling like you're constantly catching up, you can create a plan to move forward with confidence—and even start saving again. Here’s What the Process Looks Like: Review your current debts and cash flow Assess how much equity you’ve built in your home Explore consolidation options that fit your goals Create a personalized plan to streamline your payments and reduce overall costs Ready to Regain Control? If your debts are holding you back and you're ready to use the equity you've worked hard to build, let's talk. There’s no pressure—just a practical conversation about your options and how to move toward a more flexible, debt-free future. Reach out today. I’m here to help you make the most of what you already have.