Buying a Home With Friends or Siblings in Ontario

Published 12 November 2026 · By Jatin Dua, Broker of Record, RE/MAX Quantum Realty

Buying with a friend or a sibling is one of the few genuinely effective answers to GTA prices. Two incomes qualify for substantially more than one, and the costs split. It works, and I have seen it work well.

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It goes wrong in predictable ways, and almost all of them trace back to two decisions made in ten seconds at the lawyer’s office, and one document nobody drafted.

Decision one: joint tenants or tenants in common

Your lawyer will ask how you want to hold title. The answer matters enormously.

Joint tenancy

Equal undivided shares, with a right of survivorship. If one owner dies, their interest passes automatically to the surviving owner — outside the estate, regardless of what their will says.

This is usually right for spouses. It is usually wrong for friends and siblings. If you buy a house with your brother and he dies, his half comes to you and not to his children. That is rarely what either of you intended, and it is the single most common mistake in co-ownership.

Tenants in common

Separate shares, which can be unequal, with no survivorship. Each owner’s share passes under their own will.

This is normally the right structure for friends, siblings and any arrangement where the contributions are unequal. If you put in 70% of the down payment and your friend puts in 30%, tenants in common lets the title reflect that. Joint tenancy does not.

Get this right at closing. Changing it later is possible but it is extra legal work, and in some situations it has tax consequences.

Decision two: the mortgage is joint, whatever the title says

Here is the asymmetry that catches people. You can hold title 70/30. You cannot hold the mortgage 70/30.

If you are both on the mortgage, you are each liable for the whole of it. Not your share — all of it. If your co-owner stops paying, the lender comes to you for the full payment, and your credit takes the damage alongside theirs.

It also affects your own borrowing. The full mortgage balance appears on your credit profile, which affects what you can qualify for later, including on a property of your own.

This is not a reason not to do it. It is a reason to be clear-eyed about who you are doing it with, and to have the next section in place.

The document nobody drafts

A co-ownership agreement, signed before closing. This is the whole ball game, and almost nobody does it because everyone gets along at the start.

At minimum it should deal with:

Who contributed what — down payment, closing costs, and the ownership percentages those produce
Who pays what ongoing — mortgage, taxes, insurance, utilities, condo fees, and in what proportions
Repairs and improvements — the dollar threshold above which both must agree, and how an improvement one party paid for is treated at sale
What happens when one wants out — this is the clause that matters most. A right of first refusal for the other owner, a valuation method (two appraisals, averaged, is a common and workable formula), and a timeline
What happens on death, disability, job loss, marriage or a new partner moving in — the last one causes more friction than any other and is almost never addressed
Whether either of you may rent out your space, and to whom
How a deadlock gets broken — mediation, then arbitration, is cheaper than court
What happens if someone misses payments — the other covering it, and how that is recorded as a debt between you

Expect this to cost a modest legal fee. It is the best money in the transaction.

The exit nobody plans for

If there is no agreement and you cannot agree on an exit, Ontario law gives a co-owner a route: an application under the Partition Act for partition or sale of the property. In practice, for a single house or condo that cannot be physically divided, that means a court-ordered sale.

It works. It is also slow, expensive, public, and the legal costs come out of the proceeds you are arguing over. A buy-sell clause in a co-ownership agreement achieves the same outcome for a fraction of the cost, which is the argument for drafting one.

Practical points people miss

Keep a joint account for the house and run every property expense through it. Reconstructing who paid what from two sets of personal bank records, four years later, is miserable.
Insurance: make sure both owners are named insureds, and check that the policy contemplates the actual occupancy arrangement.
Taxes: each owner’s principal residence position is their own, and the rules are not symmetrical if one of you moves out and the other stays. Ask an accountant before anyone moves out, not after.
Land transfer tax and first-time buyer refunds: eligibility is individual and the refund can be affected by a co-purchaser’s status. Confirm the amount before you budget it.
Write down the plan’s horizon. “We will reassess in five years” is a far better starting point than an unspoken assumption that one of you intends to be there for twenty.

The honest summary

Co-ownership is a good tool and I would not talk anyone out of it. But hold title as tenants in common unless you specifically want survivorship, understand that the mortgage makes each of you liable for all of it, and sign a co-ownership agreement before closing that says how somebody gets out.

The friendships that survive this are the ones where the awkward conversation happened before the offer, not after.

General information, not legal or tax advice. Get a real estate lawyer to advise on title and to draft the co-ownership agreement, and an accountant on the tax side.

Sources

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