Mortgage Approval 101: GDS & TDS Explained

Christopher J. Collins • November 26, 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.


CHRIS COLLINS
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Mortgages Aren’t One-Size-Fits-All

By Christopher J. Collins • January 7, 2026
Why the Cheapest Mortgage Isn’t Always the Smartest Move Some things are fine to buy on the cheap. Generic cereal? Sure. Basic airline seat? No problem. A car with roll-down windows? If it gets you where you're going, great. But when it comes to choosing a mortgage? That’s not the time to cut corners. A “no-frills” mortgage might sound appealing with its rock-bottom interest rate, but what’s stripped away to get you that rate can end up costing you far more in the long run. These mortgages often come with severe limitations—restrictions that could hit your wallet hard if life throws you a curveball. Let’s break it down. A typical no-frills mortgage might offer a slightly lower interest rate—maybe 0.10% to 0.20% less. That could save you a few hundred dollars over a few years. But that small upfront saving comes at the cost of flexibility: Breaking your mortgage early? Expect a massive penalty. Want to make extra payments? Often not allowed—or severely restricted. Need to move and take your mortgage with you? Not likely. Thinking about refinancing? Good luck doing that without a financial hit. Most people don’t plan on breaking their mortgage early—but roughly two-thirds of Canadians do, often due to job changes, separations, relocations, or expanding families. That’s why flexibility matters. So why do lenders even offer no-frills mortgages? Because they know the stats. And they know many borrowers chase the lowest rate without asking what’s behind it. Some banks count on that. Their job is to maximize profits. Ours? To help you make an informed, strategic choice. As independent mortgage professionals, we work for you—not a single lender. That means we can compare multiple products from various financial institutions to find the one that actually suits your goals and protects your long-term financial health. Bottom line: Don’t let a shiny low rate distract you from what really matters. A mortgage should fit your life—not the other way around. Have questions? Want to look at your options? I’d be happy to help. Let’s chat.

Don’t Let Collections Derail Your Mortgage Application

By Christopher J. Collins • December 31, 2025
Can You Get a Mortgage If You Have Collections on Your Credit Report? Short answer? Not easily. Long answer? It depends—and it’s more common (and fixable) than you might think. When it comes to applying for a mortgage, your credit report tells lenders a story. Collections—debts that have been passed to a collection agency because they weren’t paid on time—are big red flags in that story. Regardless of how or why they got there, open collections are going to hurt your chances of getting approved. Let’s break this down. What Exactly Is a Collection? A collection appears on your credit report when a bill goes unpaid for long enough that the lender decides to stop chasing you—and hires a collection agency to do it instead. It doesn’t matter whether it was an unpaid phone bill, a forgotten credit card, or a disputed fine: to a lender, it signals risk. And lenders don’t like risk. Why It Matters to Mortgage Lenders? Lenders use your credit report to gauge how trustworthy you are with borrowed money. If they see you haven’t paid a past debt, especially recently, it suggests you might do the same with a new mortgage—and that’s enough to get your application denied. Even small collections can cause problems. A $32 unpaid utility bill might seem insignificant to you, but to a lender, it’s a red flag waving loudly. But What If I Didn’t Know About the Collection? It happens all the time. You move provinces and miss a final utility charge. Your cell provider sends a bill to an old address. Or maybe the collection is showing in error—credit reports aren’t perfect, and mistakes do happen. Regardless of the reason, the responsibility to resolve it still falls on you. Even if it’s an honest oversight or an error, lenders will expect you to clear it up or prove it’s been paid. And What If I Chose Not to Pay It? Some people intentionally leave certain collections unpaid—maybe they disagree with a charge, or feel a fine is unfair. Here are a few common “moral stand” collections: Disputed phone bills COVID-related fines Traffic tickets Unpaid spousal or child support While you might feel justified, lenders don’t take sides. They’re not interested in why a collection exists—only that it hasn’t been dealt with. And if it’s still active, that could be enough to derail your mortgage application. How Can You Find Out What’s On Your Report? Easy. You can check it yourself through services like Equifax or TransUnion, or you can work with a mortgage advisor to go through a full pre-approval. A pre-approval will quickly uncover any credit issues, including collections—giving you a chance to fix them before you apply for a mortgage. What To Do If You Have Collections Verify: Make sure the collection is accurate. Pay or Dispute: Settle the debt or begin a dispute process if it’s an error. Get Proof: Even if your credit report hasn’t updated yet, documentation showing the debt is paid can be enough for some lenders. Work With a Pro: A mortgage advisor can help you build a strategy and connect you with lenders who offer flexible solutions. Collections are common, but they can absolutely block your path to mortgage financing. Whether you knew about them or not, the best approach is to take action early. If you’d like to find out where you stand—or need help navigating your credit report—I’d be happy to help. Let’s make sure your next mortgage application has the best possible chance of approval.