Mortgage Approval 101: GDS & TDS Explained

Carla Sturm • September 3, 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.


Carla Sturm
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What to Expect in the Closing Process: A Step-by-Step Guide

By Carla Sturm • April 15, 2026
You’ve found the right home, your offer’s been accepted, and your financing is approved—congratulations! But before you can pick up the keys and celebrate, there’s one more important stage: the closing process. Closing is the final step in your homebuying journey, where all the paperwork, legal details, and financial transactions come together. It can feel overwhelming if you don’t know what to expect, but with the right preparation, closing can be smooth and stress-free. Here’s a step-by-step guide to help you understand the process. Step 1: Hire a Lawyer or Notary A real estate lawyer (or notary, depending on your province) handles the legal side of closing. They will: Review the purchase agreement and mortgage documents Conduct a title search to confirm the seller has the legal right to sell the property Ensure the mortgage lender is properly registered on the title Handle the transfer of funds between you, the lender, and the seller Your lawyer or notary will be your main point of contact during closing, so choose one you trust and who communicates clearly. Step 2: Finalize Your Mortgage Your lender will send the mortgage instructions directly to your lawyer or notary. At this stage: You’ll provide proof of property insurance (lenders require this before releasing funds) You’ll confirm your down payment and closing costs are available in your lawyer’s trust account The lawyer will prepare all documents for your review and signature Step 3: Pay Closing Costs Closing costs typically range from 1.5% to 4% of the purchase price. These can include: Legal fees Title insurance Land transfer tax (where applicable) Adjustments for property taxes or utilities prepaid by the seller Home inspection or appraisal fees (if not already paid) Your lawyer will provide a final statement of adjustments so you know exactly how much is due on closing day. Step 4: Sign the Paperwork A few days before closing, you’ll meet with your lawyer or notary to sign all the necessary documents, including: Mortgage agreement Title transfer Insurance confirmations Statement of adjustments Bring valid government-issued ID to this appointment. Step 5: Transfer of Funds On the day of closing: Your lender sends the mortgage funds to your lawyer Your lawyer combines these funds with your down payment and pays the seller Legal ownership of the property is transferred into your name The lender is registered on title as a secured creditor Step 6: Get the Keys! Once the paperwork is filed and the funds have cleared, your lawyer will confirm that the transaction is complete. You’ll then get the keys to your new home—officially making it yours. The Bottom Line The closing process is a series of important steps, but with the right team in place, it doesn’t have to be stressful. By working closely with your mortgage professional and lawyer, you’ll have guidance every step of the way—from signing the documents to turning the key in the front door. If you’d like help preparing for the closing process—or want a clear breakdown of your own closing costs— connect with us today.

Buying a Vacation Property or Rental? Here’s What Lenders Look For

By Carla Sturm • April 8, 2026
Owning a vacation home or an investment rental property is a dream for many Canadians. Whether it’s a cottage on the lake for family getaways or a rental unit to generate extra income, real estate can be both a lifestyle choice and a smart financial move. But before you dive in, it’s important to know what lenders look for when financing these types of properties. 1. Down Payment Requirements The biggest difference between buying a primary residence and a vacation or rental property is the down payment. Vacation property (owner-occupied, seasonal, or secondary home): Typically requires at least 5–10% down, depending on the lender and whether the property is winterized and accessible year-round. Rental property: Usually requires a minimum of 20% down. This is because rental income can fluctuate, and lenders want extra security before approving financing. 2. Property Type & Location Not all properties qualify for traditional mortgage financing. Lenders consider: Accessibility : Is the property accessible year-round (roads maintained, utilities available)? Condition : Seasonal or non-winterized cottages may not meet standard lending criteria. Zoning & Use : If it’s a rental, lenders want to ensure it complies with municipal bylaws and zoning regulations. Properties that fall outside these norms may require financing through alternative lenders, often with higher rates but more flexibility. 3. Rental Income Considerations If you’re buying a property with the intent to rent it out, lenders may factor the rental income into your mortgage application. Long-term rentals : Lenders typically accept 50–80% of the expected rental income when calculating your debt-service ratios. Short-term rentals (Airbnb, VRBO, etc.) : Many traditional lenders are cautious about using projected income from short-term rentals. Alternative lenders may be more flexible, depending on the property’s location and your financial profile. 4. Debt-Service Ratios Lenders use your Gross Debt Service (GDS) and Total Debt Service (TDS) ratios to determine if you can handle the mortgage payments alongside your other obligations. With investment or vacation properties, lenders may apply stricter guidelines, especially if your primary residence already carries a large mortgage. 5. Credit & Financial Stability Your credit score, employment history, and overall financial health still matter. Since vacation and rental properties are considered higher risk, lenders want reassurance that you can handle the additional debt—even if rental income fluctuates or the property sits vacant. 6. Insurance Requirements Rental properties often require specialized landlord insurance, and vacation homes may need coverage tailored to seasonal or secondary use. Lenders will want proof of adequate insurance before releasing mortgage funds. The Bottom Line Buying a vacation property or rental can be exciting, but financing these purchases comes with extra rules and considerations. From higher down payments to stricter property requirements, lenders want to be confident that you can handle the responsibility. If you’re considering a second property, the best step is to work with a mortgage professional who can compare lender requirements, outline your options, and find the financing that works best for you. Thinking about making your dream of a vacation or rental property a reality? Connect with us today.