Mortgage Approval 101: GDS & TDS Explained

Kambi Heywood • December 18, 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.


Kambi Heywood

Licensed Mortgage Broker

GET STARTED

Bank of Canada Rate Announcement Jan 28th, 2026

By Kambi Heywood • January 28, 2026
Bank of Canada maintains policy rate at 2¼%. FOR IMMEDIATE RELEASE Media Relations Ottawa, Ontario January 28, 2026 The Bank of Canada today held its target for the overnight rate at 2.25%, with the Bank Rate at 2.5% and the deposit rate at 2.20%. The outlook for the global and Canadian economies is little changed relative to the projection in the October Monetary Policy Report (MPR). However, the outlook is vulnerable to unpredictable US trade policies and geopolitical risks. Economic growth in the United States continues to outpace expectations and is projected to remain solid, driven by AI-related investment and consumer spending. Tariffs are pushing up US inflation, although their effect is expected to fade gradually later this year. In the euro area, growth has been supported by activity in service sectors and will get additional support from fiscal policy. China’s GDP growth is expected to slow gradually, as weakening domestic demand offsets strength in exports. Overall, the Bank expects global growth to average about 3% over the projection horizon. Global financial conditions have remained accommodative overall. Recent weakness in the US dollar has pushed the Canadian dollar above 72 cents, roughly where it had been since the October MPR. Oil prices have been fluctuating in response to geopolitical events and, going forward, are assumed to be slightly below the levels in the October report. US trade restrictions and uncertainty continue to disrupt growth in Canada. After a strong third quarter, GDP growth in the fourth quarter likely stalled. Exports continue to be buffeted by US tariffs, while domestic demand appears to be picking up. Employment has risen in recent months. Still, the unemployment rate remains elevated at 6.8% and relatively few businesses say they plan to hire more workers. Economic growth is projected to be modest in the near term as population growth slows and Canada adjusts to US protectionism. In the projection, consumer spending holds up and business investment strengthens gradually, with fiscal policy providing some support. The Bank projects growth of 1.1% in 2026 and 1.5% in 2027, broadly in line with the October projection. A key source of uncertainty is the upcoming review of the Canada-US-Mexico Agreement. CPI inflation picked up in December to 2.4%, boosted by base-year effects linked to last winter’s GST/HST holiday. Excluding the effect of changes in taxes, inflation has been slowing since September. The Bank’s preferred measures of core inflation have eased from 3% in October to around 2½% in December. Inflation was 2.1% in 2025 and the Bank expects inflation to stay close to the 2% target over the projection period, with trade-related cost pressures offset by excess supply. Monetary policy is focused on keeping inflation close to the 2% target while helping the economy through this period of structural adjustment. Governing Council judges the current policy rate remains appropriate, conditional on the economy evolving broadly in line with the outlook we published today. However, uncertainty is heightened and we are monitoring risks closely. If the outlook changes, we are prepared to respond. The Bank is committed to ensuring that Canadians continue to have confidence in price stability through this period of global upheaval. Information note The next scheduled date for announcing the overnight rate target is March 18, 2026. The Bank’s next MPR will be released on April 29, 2026. Read the January 28th, 2026 Monetary Report

Get Unbiased Advice: Work with an Independent Mortgage Pro

By Kambi Heywood • January 22, 2026
Why Work With an Independent Mortgage Professional? If you’re in the market for a mortgage, here’s the most important thing to know: Working with an independent mortgage professional can save you money and provide better options than dealing directly with a single bank. If that’s all you read—great! But if you’d like to understand why that statement is true, keep reading. The Best Mortgage Isn’t Just About the Lowest Rate It’s easy to fall for slick marketing that promotes ultra-low mortgage rates. But the lowest rate doesn’t always mean the lowest cost . The best mortgage is the one that costs you the least amount of money over time —not just the one with the flashiest headline rate. Things like: Prepayment penalties Portability Flexibility to refinance Amortization structure Fixed vs. variable terms …can all affect the true cost of your mortgage. An independent mortgage professional looks beyond the rate. They’ll help you find a product that fits your unique financial situation , long-term goals, and lifestyle—so you’re not hit with expensive surprises down the road. Save Time (and Your Sanity) Applying for a mortgage can be complicated. Every lender has different rules, documents, and policies—and trying to navigate them all on your own can be time-consuming and frustrating. When you work with an independent mortgage professional: You fill out one application They shop that application across multiple lenders You get expert advice tailored to your needs This means less paperwork , less stress , and more confidence in your options. Get Unbiased Advice That Puts You First Bank specialists work for the bank. Their job is to sell you that bank’s mortgage products—whether or not it’s the best deal for you. Independent mortgage professionals work for you. They’re provincially licensed, and their job is to help you: Compare multiple lenders Understand the fine print Make informed, long-term financial decisions And the best part? Their services are typically free to you . Mortgage professionals are paid a standardized fee by the lender when a mortgage is placed—so you get expert guidance without any out-of-pocket cost. Access More Mortgage Options When you go to your bank, you’re limited to that bank’s mortgage products. When you go to an independent mortgage professional, you get access to: Major banks Credit unions Monoline lenders (who only offer mortgages) Alternative and private lenders (if needed) That’s far more choice , and a much better chance of finding a mortgage that truly fits your needs and goals. The Bottom Line If you want to: Save money over the life of your mortgage Save time by avoiding unnecessary back-and-forth Access more lenders and products Get honest, client-first advice …then working with an independent mortgage professional is one of the smartest decisions you can make. Let’s Make a Plan That Works for You If you're ready to talk about mortgage financing—or just want to explore your options—I'm here to help. Let's connect and put together a strategy that makes sense for your goals and your future. Reach out anytime. I’d be happy to help.