What Are GDS/TDS Ratios Anyways?

Kambi Heywood • October 23, 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.


Kambi Heywood

Licensed Mortgage Broker

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Smart Steps to Get Your Home Market-Ready

By Kambi Heywood • October 9, 2025
Thinking About Selling Your Home? Start With These 3 Key Questions Selling your home is a major move—emotionally, financially, and logistically. Whether you're upsizing, downsizing, relocating, or just ready for a change, there are a few essential questions you should have answers to before you list that "For Sale" sign. 1. How Will I Get My Home Sale-Ready? Before your property hits the market, you’ll want to make sure it puts its best foot forward. That starts with understanding its current market value—and ends with a plan to maximize its appeal. A real estate professional can walk you through what similar homes in your area have sold for and help tailor a prep plan that aligns with current market conditions. Here are some things you might want to consider: Decluttering and removing personal items Minor touch-ups or repairs Fresh paint inside (and maybe outside too) Updated lighting or fixtures Professional staging Landscaping or exterior cleanup High-quality photos and possibly a virtual tour These aren’t must-dos, but smart investments here can often translate to a higher sale price and faster sale. 2. What Will It Actually Cost to Sell? It’s easy to look at the selling price and subtract your mortgage balance—but the real math is more nuanced. Here's a breakdown of the typical costs involved in selling a home: Real estate agent commissions (plus GST/HST) Legal fees Mortgage discharge fees (and possibly a penalty) Utility and property tax adjustments Moving expenses and/or storage costs That mortgage penalty can be especially tricky—it can sometimes be thousands of dollars, depending on your lender and how much time is left in your term. Not sure what it might cost you? I can help you estimate it. 3. What’s My Plan After the Sale? Knowing your next step is just as important as selling your current home. If you're buying again, don’t assume you’ll automatically qualify for a new mortgage just because you’ve had one before. Lending rules change, and so might your financial situation. Before you sell, talk to a mortgage professional to find out what you’re pre-approved for and what options are available. If you're planning to rent or relocate temporarily, think about timelines, storage, and transition costs. Clarity and preparation go a long way. The best way to reduce stress and make confident decisions is to work with professionals you trust—and ask all the questions you need. If you’re thinking about selling and want help mapping out your next steps, I’d be happy to chat anytime. Let’s make a smart plan, together.

Collections Can Prevent Mortgage Financing

By Kambi Heywood • September 25, 2025
A question that comes up from time to time when discussing mortgage financing is, “If I have collections showing on my credit bureau, will that impact my ability to get a mortgage?” The answer might have a broader implication than what you might think; let's spend a little time discussing it. Collections accounts are reported on your credit bureau when you have a debt that hasn’t been paid as agreed. Now, regardless of the reason for the collection; the collection is a result of delinquency, it’s an account you didn’t realize was in collections, or even if it’s a choice not to pay something because of moral reasons, all open collections will negatively impact your ability to secure new mortgage financing. Delinquency If you’re really late on paying on a loan, credit card, line of credit, or mortgage, and the lender has sent that account to collections, as they consider it a bad debt, this will certainly impact your ability to get new mortgage financing. Look at it this way, why would any lender want to extend new credit to you when you have a known history of not paying your existing debts as agreed? If you happen to be late on your payments and the collection agencies are calling, the best plan would be to deal with the issue head-on. Settle the debts as quickly as possible and work towards establishing your credit. Very few (if any) lenders will even consider your mortgage application with open collections showing on your credit report. If you’re unaware of bad debts It happens a lot more than you’d think; people applying for a mortgage are completely unaware that they have delinquent accounts on their credit report. A common reason for this is that collection agencies are hired simply because the lender can’t reach someone. Here’s an example. Let’s say you’re moving from one province to another for work, you pay the outstanding balance on your utility accounts, change your phone number, and make the move. And while you think you’ve paid the final amount owing, they read your meter, and there is $32 outstanding on your bill. As the utility company has no way of tracking you down, they send that amount to an agency that registers it on your credit report. You don't know any of this has happened and certainly would have paid the amount had you known it was due. Alternatively, with over 20% of credit reports containing some level of inaccuracy, mistakes happen. If you’ve had collections in the past, there’s a chance they might be reporting inaccurately, even if it's been paid out. So as far as your mortgage is concerned, it really doesn’t matter if the collection is a reporting error or a valid collection that you weren’t aware of. If it’s on your credit report, it’s your responsibility to prove it’s been remediated. Most lenders will accept documentation proving the account has been paid and won’t require those changes to reflect on your credit report before proceeding with a mortgage application. So how do you know if you’ve got mistakes on your credit report? Well, you can either access your credit reports on your own or talk with an independent mortgage advisor to put together a mortgage preapproval. The preapproval process will uncover any issues holding you back. If there are any collections on your bureau, you can implement a plan to fix the problem before applying for a mortgage. Moral Collections What if you have purposefully chosen not to pay a collection, fine, bill, or debt for moral reasons? Or what if that account is sitting as an unpaid collection on your credit report because you dispute the subject matter? Here are a few examples. A disputed phone or utility bill Unpaid alimony or child support Unpaid collections for traffic tickets Unpaid collections for COVID-19 fines The truth is, lenders don’t care what the collection is for; they just want to see that you’ve dealt with it. They will be reluctant to extend new mortgage financing while you have an active collection reporting on your bureau. So if you decide to take a moral stand on not paying a collection, please know that you run the risk of having that moral decision impact your ability to secure a mortgage in the future. If you have any questions about this or anything else mortgage-related, please connect anytime! It would be a pleasure to work with you!