Can I just add someone to my mortgage without refinancing?

No. Adding a person to an existing mortgage requires lender approval and a formal amendment to the mortgage contract. In most cases, the lender will require both borrowers to fully re-qualify for the mortgage together under current underwriting standards. This is not a simple administrative change — it is treated similarly to a mortgage refinance.

Does adding someone to my mortgage trigger land transfer tax?

It depends on the province and how the transaction is structured. Adding a person to the title (not just the mortgage) commonly triggers land transfer tax on the value of the interest being transferred. Ontario and BC are the most likely provinces where this becomes a cost. Speak to a real estate lawyer before proceeding to understand the tax implications in your province.

What is the difference between adding someone to the title vs the mortgage?

The mortgage and the title are separate. You can be on the mortgage (financially responsible for the debt) without being on the title (not a legal owner), and vice versa. Most lenders require both borrowers to be on both. Your lawyer handles the title change; your lender handles the mortgage amendment.

What happens financially if the other person stops paying?

Both borrowers are jointly and severally liable for the entire mortgage. This means the lender can pursue either borrower for the full balance — not just 50%. If your co-borrower stops paying, your credit and property are at risk. The co-borrower relationship does not protect one party from the other party's failure to pay.

How does adding a co-borrower affect my debt ratios?

When re-qualifying, the lender looks at the combined income and combined debts of both borrowers. Adding someone with high existing debt obligations may not improve your qualification much, or could hurt it. Conversely, adding a high-income person with low debt is the most common reason people add a co-borrower — to qualify for a larger mortgage.

Can I remove someone from my mortgage later?

Yes, but removal also requires lender approval and the remaining borrower must qualify for the full mortgage on their own. This is called an assumption. If the remaining borrower cannot qualify independently, the only alternative is to sell the property or refinance. Both trigger a full underwriting review and potential discharge/reinstatement costs.

Before You Add Someone to Your Mortgage in Canada

Short Answer

Adding someone to your mortgage is not a simple addition — it requires re-qualifying the mortgage together, updating the legal title, and potentially triggering land transfer tax. It binds both parties to the full debt and makes removal complex later.

Why People Add Someone to a Mortgage

Reason	Notes
Increase combined income to qualify for a larger mortgage	Most common reason — lender sees two incomes
Add a spouse or partner after purchase	Often done following marriage or common-law status
Add an adult child to assist aging parents	Helps parents maintain the property or qualify for refinance
Rebuild credit history for co-borrower	Both borrowers’ credit is reported on the mortgage going forward

Step 1: Get Lender Approval

You cannot add someone to your mortgage unilaterally. You must apply through your lender:

Step	What happens
Submit application	Both borrowers apply as if it were a new mortgage
Full underwriting	Lender reviews credit, income, debts for both parties
Stress test applied	Both must qualify at the qualifying rate (contract rate + 2% or 5.25%, whichever is higher)
Mortgage amendment issued	If approved, lender creates a legal amendment
Legal work required	A real estate lawyer prepares the title transfer and mortgage documentation

Cost: Legal fees typically $1,000–$2,500. Plus potential land transfer tax (see below). Plus appraisal if required ($300–$600).

Step 2: Understand Land Transfer Tax Risk

When you add someone to the title (which most lenders require alongside the mortgage), you are transferring a share of the property to them. This may trigger land transfer tax.

Province	Land transfer tax on title addition?	Notes
Ontario	Yes — on value of interest transferred	Toronto has an additional municipal LTT
British Columbia	Yes — on value of interest transferred	PTT at 1% on first $200K, 2% above
Alberta	No provincial LTT	Minimal land title transfer fee only
Quebec	Yes (Welcome Tax)	Based on municipal assessment
Other provinces	Varies	Check with provincial registry

Example (Ontario): You own a $600,000 home. Adding a partner at 50% means transferring $300,000 in value. LTT at ~1.5% = ~$4,500 in Ontario LTT. This is paid by the person receiving the interest (the new co-owner).

Step 3: Joint Tenancy vs Tenancy in Common

When the title is updated, you must decide how the ownership is structured:

Ownership type	How it works	Right of survivorship
Joint tenancy	Each owner holds an undivided interest equally	Yes — on death, interest passes automatically to surviving owner(s)
Tenancy in common	Each owner holds a specified percentage	No — on death, interest goes to the estate per the will

Couples often choose joint tenancy for the survivorship benefit. Partners with different ownership shares or estate planning needs typically prefer tenancy in common.

Step 4: Legal Agreement for Non-Spouses

If adding a non-spouse (parent, sibling, business partner), a co-ownership agreement is strongly recommended:

Item to address in agreement	Why
Each party’s financial contribution and ownership percentage	Prevents disputes if one party contributes more
Who pays mortgage, taxes, insurance, maintenance	Defines ongoing obligations
What happens if one party wants to sell	Buyout rights, forced sale
What happens on death of one co-owner	Survivorship or estate distribution
What happens on relationship breakdown	Process for resolving the shared asset

A real estate lawyer can draft this. Skipping it risks expensive litigation later.

Step 5: Removing Someone Later

Adding is easier than removing. Removal (assumption) requires:

Step	Details
Remaining borrower re-qualifies alone	Full stress test at current qualifying rate
Lender approval	Not guaranteed — may be declined if solo qualification fails
Title updated via lawyer	Same legal cost as adding ($1,000–$2,500)
Potential discharge and reinstatement	Depending on lender and timing

In a separation, if neither party can buy out the other and qualify alone, the property must often be sold. This is a common and expensive outcome when co-ownership exits are not planned for.

Before You Add Someone to Your Mortgage: Checklist

Lender contacted and process confirmed — approval is not automatic
Both borrowers’ credit, income, and debts reviewed together
Stress test qualification confirmed with combined financials
Land transfer tax cost estimated for your province
Decision made on joint tenancy vs tenancy in common
Co-ownership agreement drafted (for non-spousal co-borrowers)
Real estate lawyer retained for title and mortgage amendment
Implications of future removal or separation considered
Impact on each borrower’s TDS ratio and future borrowing capacity confirmed

Bottom Line

Adding someone to your mortgage locks both parties into full joint liability for the debt, requires a full requalification, and creates a title change that may cost thousands in land transfer tax. It is a significant legal and financial step that should be done with a real estate lawyer and a clear written agreement for what happens if the arrangement needs to change.