Mortgage Approval 101: GDS & TDS Explained

Hummingbird Mortgages • 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.


Nate Atkin
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By Hummingbird Mortgages January 7, 2026
Alternative Lending in Canada: What It Is and When It Makes Sense Not everyone fits into the traditional lending box—and that’s where alternative mortgage lenders come in. Alternative lending refers to any mortgage solution that falls outside of the typical big bank offerings. These lenders are flexible, creative, and focused on helping Canadians who may not qualify for traditional financing still access the real estate market. Let’s explore when alternative lending might be the right fit for you. 1. You Have Damaged Credit Bad credit doesn’t have to mean your homeownership dreams are over. Many alternative lenders take a big-picture approach . While credit scores matter, they’ll also look at: Stable employment Consistent income Size of your down payment or existing equity If your credit has taken a hit but you can demonstrate strong income and savings—or have a solid explanation for past credit issues— an alternative lender may approve your mortgage when a bank won’t. Pro tip: Use an alternative mortgage as a short-term solution while you rebuild your credit, then refinance into a traditional mortgage with better terms down the line. 2. You're Self-Employed Being your own boss has its perks—but mortgage approval isn’t usually one of them. Traditional lenders require verifiable, consistent income—often two years’ worth. But self-employed Canadians typically write off significant expenses, reducing their declared income. Alternative lenders are more flexible and understanding of self-employed income structures. If your business is profitable and your personal finances are healthy, you may qualify even with lower stated income. Even if interest rates are slightly higher, this option is often worth it—especially when balanced against tax planning and business deductions . 3. You Earn Non-Traditional Income Today’s income sources aren’t always conventional. If you earn through: Airbnb rentals Tips and gratuities Rideshare or delivery apps (like Uber or Uber Eats) Commissions or contracts You might face challenges with traditional lenders. Alternative lenders are often more willing to work with these non-standard income streams , especially if the rest of your mortgage application is strong. Some will consider a shorter income history or evaluate your average earnings in a more flexible way. 4. You Need Expanded Debt-Service Ratios Canada’s mortgage stress test has made it harder for many borrowers to qualify with big banks. Alternative lenders can offer more generous debt-service ratio limits —meaning you might be able to qualify for a larger mortgage or a more suitable home, especially in competitive markets. While traditional GDS/TDS limits typically sit at 35/42 or 39/44 (depending on your credit), some alternative lenders will go higher, especially if: You have a larger down payment Your loan-to-value ratio is lower Your overall financial profile is strong It’s not a free-for-all—but it’s more flexible than bank lending. So, Is Alternative Lending Right for You? Alternative lending is designed to offer solutions when life doesn’t fit the traditional mold . Whether you're rebuilding credit, running your own business, or earning income in new ways, this path could help you get into a home sooner—or keep your current one. And here’s the key: You can only access alternative lenders through the mortgage broker channel . Let’s Explore Your Options Not sure where you fit? That’s okay. Every mortgage story is unique—and I’m here to help you write yours. If you’re curious about alternative mortgage products, want a second opinion, or need help getting approved, let’s talk . I’d be happy to help you explore the best solution for your situation. Reach out anytime. It would be a pleasure to work with you.
By Hummingbird Mortgages December 31, 2025
Mortgage Registration 101: What You Need to Know About Standard vs. Collateral Charges When you’re setting up a mortgage, it’s easy to focus on the rate and monthly payment—but what about how your mortgage is registered? Most borrowers don’t realize this, but there are two common ways your lender can register your mortgage: as a standard charge or a collateral charge . And that choice can affect your flexibility, future borrowing power, and even your ability to switch lenders. Let’s break down what each option means—without the legal jargon. What Is a Standard Charge Mortgage? Think of this as the “traditional” mortgage. With a standard charge, your lender registers exactly what you’ve borrowed on the property title. Nothing more. Nothing hidden. Just the principal amount of your mortgage. Here’s why that matters: When your mortgage term is up, you can usually switch to another lender easily —often without legal fees, as long as your terms stay the same. If you want to borrow more money down the line (for example, for renovations or debt consolidation), you’ll need to requalify and break your current mortgage , which can come with penalties and legal costs. It’s straightforward, transparent, and offers more freedom to shop around at renewal time. What Is a Collateral Charge Mortgage? This is a more flexible—but also more complex—type of mortgage registration. Instead of registering just the amount you borrow, a collateral charge mortgage registers for a higher amount , often up to 100%–125% of your home’s value . Why? To allow you to borrow additional funds in the future without redoing your mortgage. Here’s the upside: If your home’s value goes up or you need access to funds, a collateral charge mortgage may let you re-borrow more easily (if you qualify). It can bundle other credit products—like a line of credit or personal loan—into one master agreement. But there are trade-offs: You can’t switch lenders at renewal without hiring a lawyer and paying legal fees to discharge the mortgage. It may limit your ability to get a second mortgage with another lender because the original lender is registered for a higher amount than you actually owe. Which One Should You Choose? The answer depends on what matters more to you: flexibility in future borrowing , or freedom to shop around for better rates at renewal. Why Talk to a Mortgage Broker? This kind of decision shouldn’t be made by default—or by what a single lender offers. An independent mortgage professional can help you: Understand how your mortgage is registered (most people never ask!) Compare lenders that offer both options Make sure your mortgage aligns with your future goals—not just today’s needs We look at your full financial picture and explain the fine print so you can move forward with confidence—not surprises. Have questions? Let’s talk. Whether you’re renewing, refinancing, or buying for the first time, I’m here to help you make smart, informed choices about your mortgage. No pressure—just answers.