Who this is for: Owners who already carry two loans on the home, have equity left after both, and need a specific sum that a refinance or consolidation of the existing loans cannot provide.
On this page
Most homeowners never need a third mortgage, and most lenders would rather not write one. It exists for a narrow set of cases: a home with a lot of value, two loans already on it, and a need for money that no one will refinance. Because it ranks last, it is the most expensive and the least forgiving position on the title. This page explains why and what to try before you sign.
What a third mortgage is
A mortgage is a loan registered against a property. The Financial Consumer Agency of Canada describes a second mortgage as a second loan on your home, with features like a first mortgage and usually a higher rate because the lender sees more risk. A third mortgage repeats the pattern one step further down. It is another loan registered behind the first and the second.
The order matters when the home is sold or taken over because of default. The first lender is paid first, the second next, and the third from whatever is left. A HELOC secured on your home can sit in one of those positions as well, so a third charge is sometimes a line of credit on top of a second mortgage.
When it makes sense
It makes sense in a small number of situations. One is when the equity is large relative to the debts. If a home is worth much more than the three loans put together, the third lender’s position is safer, and the cost can be lower. The example above shows how little room is left on an ordinary home.
Another is when changing the first or second loan would cost too much. A first mortgage at a rate you want to keep, or a second with a penalty to break, can be a reason to add a loan rather than replace what is there.
A third also fits a short, specific, funded need, such as paying a tax bill with a sale already under contract. In each case the exit should be clear and dated.
When it makes things worse
It makes things worse when it is the way to avoid a harder conversation. Borrowing again to pay the payments on the first two loans is a sign the debt is already too large. A third loan stretches the problem and adds fees at the highest price on the home.
It also makes things worse when the home value is uncertain. A small fall in market value can wipe out the equity behind the third position, as the third worked example above shows, and that is exactly when a lender worries most about getting paid.
If you cannot meet the combined payments in a bad month, think again. Three payments on one home, each with its own due date, can be hard to track and harder to survive when income dips.
What it really costs
The second worked example shows a $30,000 third loan costing $7,050 for one year, or 23.5% of the amount borrowed. The fixed costs are the same on small loans as on large ones: legal fees, appraisal and title work. Per the agency, expect to pay appraisal, title search, title insurance and legal fees, and sometimes a mortgage loan insurance premium.
Add the cost on the other loans too. If adding a third triggers changes to the first, a lender may charge for the change. The agency says that your lender may need to change the terms of your original mortgage agreement when you borrow against your equity.
Run the figures in the calculator for the stacked payments rather than looking at the third loan alone, and ask for the total cost in dollars in writing.
The risk to the home
Three lenders hold claims on one home. Any one of them can act if you miss a payment, and a default on one may be a default on the others, depending on the paperwork. The agency warns that failing to repay a loan secured on your home can lead to serious consequences, including foreclosure.
The third worked example shows the other danger. When the sale price is poor, the lenders at the bottom may not be repaid in full, and you may still owe them the difference. A third mortgage lender knows this, so the cost and the terms reflect it.
Keep paying the first and second mortgages on time. They are the loans that move first.
Options to try first
Ask whether a single refinance can replace the existing loans. The agency lists consolidating into a lower-interest product as one way to manage debt, and warns that it can stretch repayment and raise total interest. Compare that outcome with adding a loan on top, using the equity takeout refinance page as a starting point.
Ask whether the first lender will add to the first mortgage at renewal, or whether a HELOC with your bank could work. The agency says HELOC rates are usually variable and that the lender can change the rate if it notifies you in writing. Compare it using the HELOC and second mortgage comparison.
Other options include selling the home, a smaller amount of borrowing, family help documented by a lawyer, and, if debts are unmanageable, a meeting with a Licensed Insolvency Trustee.
How the exit works
The exit is the most important part of a third mortgage. Write down the date it is due and where the money comes from: a sale, a refinance that pays off all three loans, or a known sum. A bank refinance depends on your credit, your income and the appraisal at that time. Test it against a lower appraisal and a higher interest rate.
Ask what it costs to extend and what happens if you are late. If the answer to “where does the money come from” is “I hope to refinance”, pause before you sign.
What to ask before you sign
- The total cost of borrowing in dollars for the full term, with every fee shown.
- What you will owe on the last day.
- Whether the first and second lenders must consent, and who checks.
- What it costs to extend, and what a late payment triggers.
- What you would owe if the home sold for less than expected.
- The name of the licensed professional and how to check their licence with your provincial regulator.
If you want to speak with a licensed mortgage professional in your province, you can check your options. You are free to say no.
How much room is left on a $500,000 home that already carries two loans
Made-up values. Uses the general ceiling of 80% of appraised value that the Financial Consumer Agency of Canada describes for borrowing against a home. Real lenders set lower limits for a third position.
- 80% of the $500,000 appraised value
- $400,000
- First mortgage balance
- $250,000
- Second mortgage balance
- $100,000
- Most a third loan could add at that ceiling
- $50,000
$500,000 x 0.80
A $30,000 third mortgage held for one year
Made-up figures only. An assumed 14% interest-only rate for one year, an assumed 3% lender fee, 1.5% broker fee and $1,500 for legal, appraisal and title.
- Interest for one year
- $4,200
- Lender fee
- $900
- Broker fee
- $450
- Legal, appraisal and title
- $1,500
- Cost to borrow for one year
- $7,050
$30,000 at 14%
3% of $30,000
1.5% of $30,000
What a third lender might recover on a weak sale
Made-up figures. The same three loans ($250,000, $100,000 and the $30,000 third) and an assumed sale price of $330,000 less an assumed 5% in selling costs.
- Sale price after 5% costs
- $313,500
- Paid to the first lender
- $250,000
- Paid to the second lender
- $63,500
- Left for the third lender
- $0
$330,000 minus $16,500
all that remains of $100,000 owed
Questions people ask
Why is a third mortgage more expensive than a second?
Priority decides who is paid first when a home is sold, and the third lender is paid after the first two. Less is likely to be left for them, so they charge more and ask for more equity. The same logic explains why a second costs more than a first.
Do I need the first and second lenders to agree?
Your mortgage terms and any later agreements may restrict extra loans on the property, and a lender can object. A lawyer checks the existing documents before a new loan is registered. Ask the licensed professional to confirm this step is covered in the closing.
Is a third mortgage the same as a HELOC on top of a second mortgage?
They can occupy the same position, but a HELOC lets you borrow and repay up to a limit, while a third mortgage is normally a lump sum with a fixed term. Both rank behind the loans already registered, and both put the home at risk.
Can I just replace all three loans with one?
Sometimes, through a refinance with a bank or a private first mortgage that pays off the others. That may cost less overall and leave one payment, but breaking an existing mortgage can carry a penalty. Ask for the full figures on both routes.
What happens to a third mortgage if the home sells for less?
The first lender is paid in full first, then the second, and the third receives whatever remains. If the price falls short, the third lender may not be fully repaid and can still pursue you for the balance. Check how that works in your province.