How Mortgage Rates Work: Fixed vs. Variable

Tim Lyon • September 26, 2025

What affects mortgage rates? Does the Bank of Canada rate affect fixed-rate mortgages? These are questions that come up all the time, so in this this post, I’ll explain how fixed and variable rates are determined, why they don’t always move together, and what that means for you as a borrower.


But to start with the short answer: While Bank of Canada announcements immediately impact variable rates, fixed rates usually have those expectations already baked in long before the announcement. That’s because fixed rates are forward-looking — they reflect where markets think rates are headed, not just where they are today.


What Are Fixed and Variable Rates?

Fixed Rate

The interest rate stays the same for the entire mortgage term. Payments remain consistent, no matter what happens in the market.


Variable Rate

The interest rate changes during the mortgage term, moving up or down depending on the lender’s prime rate. Payments may stay the same (VRM) or change (ARM).


How Do Fixed Rates Work?

When you choose a fixed rate, the lender is guaranteeing your rate for the length of your term. To do this, they need to estimate what a fair rate will be over that time. This makes fixed rates more forward-looking — they often reflect not just today’s conditions, but also what the market expects to happen in the future.


Key Points About Fixed Rates
  • Strongly influenced by the Canadian bond market (especially the 5-year government bond yield).
  • Lenders adjust their fixed rates based on investor expectations for inflation and future interest rates.
  • Often, Bank of Canada moves are already baked into fixed rates before they happen.


Example

If bond yields suggest that rates will rise in the next year, lenders may increase fixed rates now, even if the Bank of Canada hasn’t made a move yet.


How Do Variable Rates Work?

Variable rates move directly with the Bank of Canada’s overnight rate. When the Bank of Canada raises or lowers its rate, lenders adjust their prime rate accordingly, and variable mortgages follow.


For borrowers, the most important detail is the discount from prime, because that sets the actual rate you pay. For example, if prime is 4.95% and your mortgage is Prime – 0.5%, your rate is 4.45%.


The discounts lenders offer change over time. In periods of economic uncertainty, lenders usually shrink the discount they offer, which can make new variable mortgages less attractive even if prime is coming down.


Key Points About Variable Rates
  • Directly tied to the Bank of Canada’s overnight rate, which is reviewed eight times a year.
  • Banks adjust their prime rate in response to these moves.
  • Your actual rate = Prime – discount (e.g., Prime – 0.5%).


Example

If prime is 4.95% and your mortgage is Prime – 0.5%, your rate is 4.45%. If the Bank of Canada cuts rates by 0.25%, prime drops to 4.70%, and your rate automatically drops to 4.20%.


Why Don’t Fixed and Variable Always Move Together?

  • Fixed rates reflect the bond market, which looks ahead at where rates and inflation may go.
  • Variable rates respond directly to Bank of Canada decisions, reflecting current conditions.
  • This is why fixed rates can fall while variable rates stay flat, or vice versa.


Next Steps

If you’re deciding between fixed and variable, understanding how each is set is the first step. The next is to match the right mortgage type to your budget and comfort with risk. If you’d like to review which option works best for you, I’d be happy to help.


Need help with your mortgage? Book a consultation or call 778-988-8409.


Mortgage Term Glossary

Amortization: The total length of time it will take to pay off your mortgage completely (typically 25–30 years in Canada).
Bond Yield:
The return investors get from government bonds. Used as a benchmark for fixed mortgage rates.
Discount (Variable Rate):
The amount subtracted from prime to determine your actual mortgage rate.
Fixed Rate:
An interest rate that stays the same for the entire mortgage term.
Mortgage Term:
The length of your mortgage contract with your lender (typically 1–5 years), after which you need to renew.
Overnight Rate:
The interest rate at which major banks borrow and lend money to each other, set by the Bank of Canada.
Prime Rate:
The interest rate banks use as a baseline for loans, influenced by the Bank of Canada’s overnight rate.
Variable Rate:
An interest rate that changes during your mortgage term based on lender prime rates.

Tim Lyon

Mortgage Consultant

By Tim Lyon October 28, 2025
If you're buying a home with less than 20% down, you'll need something called an insured mortgage. Many borrowers find this confusing at first, especially since it doesn’t refer to insurance for you, the borrower. That’s why I have put together this straightforward breakdown so you understand what insured mortgages are, why they exist, and how they affect your purchase. What Is an Insured Mortgage? A mortgage must be insured when a borrower makes a down payment of less than 20% on a home purchase. The insurance protects the lender (not the borrower) in case the borrower defaults. The insurance is guaranteed by the federal government. So, why do we have this program? It allows borrowers to buy homes with smaller down payments and higher loan-to-value (LTV) ratios. Higher loan-to-value mortgages are inherently more risky because there is not much cushion if the housing market starts to decline. For example, if someone buys a $500,000 home with only 5% down ($25,000), they’ll need a $475,000 mortgage—this is a 95% LTV . If the market drops and the home’s value falls to $470,000, the mortgage would still be $475,000. If the borrower stopped making payments, the lender could lose money after selling the home and paying costs. That kind of loss, multiplied across thousands of borrowers, could threaten the stability of the entire banking system (as we saw in the U.S. in 2008). The mortgage insurance system is designed to prevent that scenario by spreading risk and keeping lenders protected. How Does the Insurance Work? You, the borrower, pay the insurance premium. It's typically added directly to your mortgage balance rather than paid upfront. The cost depends on your down payment size and amortization. Example: Purchase price: $500,000 Down payment: $25,000 (5%) Mortgage amount: $475,000 Insurance premium: 4.2% = $19,950 Total new mortgage: $494,950 The insurance does add cost, but insured mortgages usually offer slightly lower interest rates because the lender's risk is minimal. The rate savings don't fully offset the premium, but they help. The Insurer’s Role For insured mortgages, the insurer’s approval is the most important part of the process. If the insurer won’t approve the file, no lender can. Once the insurer signs off, we can typically find a lender to fund the loan. Canada has three mortgage insurers: CMHC (public) Sagen (private) Canada Guaranty (private) All of the insurers are backed by government guarantees and have to follow similar rules, but each has a few unique programs. Lenders usually choose the insurer, though I sometimes work with them to send a file to a specific insurer if it benefits the borrower. Qualification Rules Because insured mortgages are government-backed, the rules are strict: Debt ratios: 39% of your income can go toward your stress-tested mortgage payment, property taxes, heat, and half of condo fees 44% of your income can go toward the above plus your other debts Down payment: 5% on the first $500,000, 10% on the remainder Maximum purchase price: $1.5 million Amortization: Maximum of 25 years for most buyers; up to 30 years for first-time buyers who qualify under the new federal program Unlike with an uninsured mortgage, where lenders may have some flexibility if your income ratios are slightly above the limits, there is no discretion on an insured mortgage. If your ratios exceed the limits even a little bit, the insurer will decline the application. The Approval Process The process is similar to an uninsured mortgage, with one extra step: We submit your mortgage application to the lender of choice They do their initial review If that looks good, they package it up and send it to the insurer Once the insurer has reviewed and approved it, the file comes back to the lender for final review and approval Common Misunderstandings About Insured Mortgages Many borrowers are surprised to learn the following facts about insured mortgages: You do not need to be a first-time homebuyer to buy with less than 20% down You cannot buy an investment property with less than 20% down You can buy a second home with less than 20% down You cannot refinance an insured mortgage and keep the insurance. If you have an insured mortgage and do refinance, you will lose the insurance. This mostly affects the lender, but it also moves you to uninsured rates. Why Choose an Insured Mortgage? Given the cost and restrictions, why would anyone choose an insured mortgage? The main reason is accessibility . It allows you to buy a home without saving a full 20% down payment, which is increasingly difficult with high home prices and living costs. It can also be a strategic choice. Some buyers prefer to keep more of their savings invested or diversified instead of tying everything up in a down payment. If your investments are earning more than your mortgage costs, keeping that money invested might make financial sense. Real-World Example Let's say you're buying a $600,000 home. Here's how the costs compare between the minimum down payment for an insured mortgage and the minimum down payment for an uninsured mortgage:
By Tim Lyon October 20, 2025
The part of mortgage approval nobody likes but everyone needs