What Are GDS/TDS Ratios Anyways?

Erik Sepper • March 5, 2025

One of the major qualifiers lenders look at when considering your application for mortgage financing is your debt service ratios.


Now, before we get started, if you prefer to have someone walk through these calculations with you, assess your financial situation, and let you know exactly where you stand, let’s connect. There is no use in dusting off the calculator and running the numbers yourself when we can do it for you!


However, if you’re someone who likes to know the nitty-gritty of how things work instead of simply accepting that's just the way it is, this article is for you. But be warned, there are a lot of mortgage words and some math ahead; with that out of the way, let’s get started!

 

“Debt servicing” is the measure of your ability to meet all of your financial obligations. There are two ratios that lenders examine to determine whether you can debt service a mortgage.


The first is called the “gross debt service” ratio, or GDS, which is the percentage of your monthly household income that covers your housing costs. The second is called the “total debt service” ratio, or TDS, which is the percentage of your monthly household income covering your housing costs and all your other debts.


GDS is your income compared to the cost of financing the mortgage, including your proposed mortgage payments (principal and interest), property taxes, and heat (PITH), plus a percentage of your condo fees (if applicable).


Here’s how to calculate your GDS.


Principal + Interest + Taxes + Heat / Gross Annual Income


Your TDS is your income compared to your GDS plus the payments made to service any existing debts. Debts include car loans, line of credit, credit card payments, support payments, student loans, and anywhere else you’re contractually obligated to make payments.


Here’s how to calculate your TDS.


Principal + Interest + Taxes + Heat + Other Debts / Gross Annual Income


With the calculations for those ratios in place, the next step is to understand that each lender has guidelines that outline a maximum GDS/TDS. Exceeding these guidelines will result in your mortgage application being declined, so the lower your GDS/TDS, the better.


If you don’t have any outstanding debts, your GDS and TDS will be the same number. This is a good thing!


The maximum ratios vary for conventional mortgage financing based on the lender and mortgage product being offered. However, if your mortgage is high ratio and mortgage default insurance is required, the maximum GDS is 39% with a maximum TDS of 44%.


So how does this play out in real life? Well, let’s say you’re currently looking to purchase a property with a payment of $1700/mth (PITH), and your total annual household income is $90,000 ($7500/mth). The calculations would be $1700 divided by $7500, which equals 0.227, giving you a gross debt service ratio of 22.7%.


A point of clarity here. When calculating the principal and interest portion of the payment, the Government of Canada has instituted a stress test. It requires you to qualify using the government's qualifying rate (which is higher), not the actual contract rate. This is true for both fixed and variable rate mortgages.


Now let’s continue with the scenario. Let’s say that in addition to the payments required to service the property, you have a car payment of $300/mth, child support payments of $500/mth, and between your credit cards and line of credit, you’re responsible for another $700/mth. In total, you pay $1500/mth. So when you add in the $1700/mth PITH, you arrive at a total of $3200/mth for all of your financial obligations. $3200 divided by $7500 equals 0.427, giving you a total debt service ratio of 42.7%.


Here’s where it gets interesting. Based on your GDS alone, you can easily afford the property. But when you factor in all your other expenses, the TDS exceeds the allowable limit of 42% (for an insured mortgage anyway). So why does this matter? Well, as it stands, you wouldn’t qualify for the mortgage, even though you are likely paying more than $1700/mth in rent.


So then, to qualify, it might be as simple as shuffling some of your debt to lower payments. Or maybe you have 10% of the purchase price saved for a downpayment, changing the mortgage structure to 5% down and using the additional 5% to pay out a portion of your debt might be the difference you need to bring it all together.


Here’s the thing, as your actual financial situation is most likely different than the one above, working with an independent mortgage professional is the best way to give yourself options. Don’t do this alone. Your best plan is to seek and rely on the advice provided by an experienced independent mortgage professional. While you might secure a handful of mortgages over your lifetime, we do this every day with people just like you.


It’s never too early to start the conversation about mortgage qualification. Going over your application and assessing your debt service ratios in detail beforehand gives you the time needed to make the financial moves necessary to put yourself in the best financial position.


So if you find yourself questioning what you can afford or if you want to discuss your GDS/TDS ratios to understand the mortgage process a little better, please get in touch. It would be a pleasure to work with you, we can get a preapproval started right away.


ERIK SEPPER 
MORTGAGE AGENT

CONTACT ME

Co-Signing a Mortgage in Canada: Pros, Cons & What to Expect

By Erik Sepper • March 11, 2026
Co-Signing a Mortgage in Canada: Pros, Cons & What to Expect Thinking about co-signing a mortgage? On the surface, it might seem like a simple way to help someone you care about achieve homeownership. But before you sign on the dotted line, it’s important to understand exactly what co-signing means—for them and for you. You’re Fully Responsible When you co-sign, your name is on the mortgage—and that makes you just as responsible as the primary borrower. If payments are missed, the lender won’t only go after them; they’ll come after you too. Missed payments or default can damage your credit score and put your financial health at risk. That’s why trust is key. If you’re going to co-sign, make sure you have a clear picture of the borrower’s ability to manage payments—and consider monitoring the account to protect yourself. You’re Committed Until They Can Stand Alone Co-signing isn’t temporary by default. Even once the initial mortgage term ends, you won’t automatically be removed. The borrower has to re-qualify on their own, and only then can your name be taken off. If they don’t qualify, you stay on the mortgage for another term. Before agreeing, talk openly about expectations: How long might you be on the mortgage? What’s the plan for eventually removing you? Having these conversations upfront prevents surprises later. It Affects Your Own Borrowing Power When lenders calculate your debt service ratios, the co-signed mortgage counts as your debt—even if you never make a payment on it. This could reduce how much you’re able to borrow in the future, whether it’s for your own home, an investment property, or even refinancing. If you see another mortgage in your future, you’ll want to consider how co-signing could limit your options. The Upside: Helping Someone Get Ahead On the positive side, co-signing can be life-changing for the borrower. You could be helping a family member or friend buy their first home, start building equity, or take an important step forward financially. If handled with clear expectations and trust, it can be a meaningful way to support someone you care about. The Bottom Line Co-signing a mortgage comes with both risks and rewards. It’s not a decision to take lightly, but with careful planning, transparency, and professional advice, it can be done responsibly. If you’re considering co-signing—or want to explore safer alternatives—let’s connect. I’d be happy to walk you through what to expect and help you decide if it’s the right move for you.

Your Guide to Real Estate Investment in Canada

By Erik Sepper • March 4, 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.

Breaking Down the Real Costs of Homeownership

By Erik Sepper • February 25, 2026
Don’t Forget About Closing Costs When planning to buy a home, most people focus on saving for the down payment. But the truth is, that’s only part of the equation. To actually finalize the purchase, you’ll also need to budget for closing costs —the out-of-pocket expenses that come up before you get the keys. Closing costs can add up quickly, which is why they should be part of your pre-approval conversation right from the start. Lenders will even require proof that you’ve got enough funds set aside. For example, if you’re getting an insured (high-ratio) mortgage, you’ll need at least 1.5% of the purchase price available in addition to your down payment. That means a 10% down payment actually requires 11.5% of the purchase price in cash to make everything work. Let’s break down some of the most common expenses you should prepare for: 1. Home Inspection & Appraisal Inspection : Paid by you, this gives peace of mind that the property is in good shape and doesn’t have hidden problems. Appraisal : Required by the lender to confirm value. Sometimes this is covered by mortgage insurance, sometimes by you. 2. Legal Fees A lawyer or notary is required to handle the title transfer and make sure the mortgage is properly registered. Legal fees are often one of the larger closing costs—unless you’re also responsible for property transfer tax. 3. Taxes Many provinces charge a property or land transfer tax based on the home’s purchase price. These fees can range from hundreds to thousands of dollars, so you’ll want to factor them in early. 4. Insurance Property insurance is mandatory—lenders won’t release funds without proof that the home is insured on closing day. Optional coverage like mortgage life, disability, or critical illness insurance may also be worth considering depending on your financial plan. 5. Moving Costs Whether you’re renting a truck, hiring movers, or bribing friends with pizza and gas money, moving comes with expenses. Cross-country moves especially can be surprisingly pricey. 6. Utilities & Deposits Setting up new services (electricity, water, internet) can involve connection fees or deposits, particularly if you don’t already have a payment history with the utility provider. Plan Ahead, Stress Less This list covers the big-ticket items, but every purchase is unique. That’s why it pays to have an accurate estimate of your personal closing costs before you make an offer. If you’d like help planning ahead—or want a breakdown tailored to your situation—let’s connect. I’d be happy to walk you through the numbers and make sure you’re fully prepared.