Co-Buying Property in Australia: How to Team Up to Beat Affordability (Without Risking the Friendship)

The single income that bought a starter home a generation ago now barely covers the deposit. So buyers are running the numbers and landing on the obvious answer: two names on the contract beat one. Co-buying property in Australia has gone from an awkward fallback to a genuine strategy, and couples are far from the only ones using it.

Siblings are buying together. Mates are splitting a deposit four ways, and plenty of parents are now going on the loan with their adult kids. It can work brilliantly. Skip the boring paperwork and it can also turn a good friendship into a courtroom story. Below: how to team up properly, which ownership structure to pick, the lending trap nobody warns you about, and how to plan your exit before you sign.

What is co-buying property in Australia?

Co-buying means two or more people purchasing a property together, pooling their deposits and combining their borrowing power to get over the line. The co-buyers might be a couple, but increasingly they are not. According to ASIC's Moneysmart, buying with others covers friends, siblings, parents and adult children, and even unrelated buyers who decide a shared purchase beats renting forever.

The appeal is obvious once you look at the affordability picture. Dwelling values have climbed faster than incomes for years, and the deposit hurdle alone keeps single buyers parked on the sidelines for a long time. When the wait is that long, splitting the cost with someone you trust starts to look less like a compromise and more like the only realistic way in. We covered the brutal arithmetic of that upfront cost in the $168,000 deposit reality, and co-buying is one of the few levers that actually moves the needle.

Who co-buys: friends, siblings, parents and adult children, and unrelated buyers

There is no single profile. A few patterns turn up again and again:

• Friends: Two or three mates who would rather own a slice of a house than keep paying off a landlord's mortgage. Buying a house with friends is the headline-grabbing version, and the riskiest if it is done on a handshake.
• Siblings: Often the most natural fit, since family money and expectations are already shared. Some siblings buy an investment property together before either can afford their own home.
• Parents and adult children: A parent goes on the loan to lift borrowing capacity or contributes the deposit, while the child lives in and eventually buys them out. Buying property with family is common, but it carries the same legal risks as any other arrangement.
• Unrelated buyers: Colleagues or acquaintances pooling resources purely as a financial decision. This is where a watertight agreement matters most.

Whoever you are teaming up with, the legal and lending mechanics are the same. The relationship does not change the rules. It just changes how uncomfortable it gets when something goes wrong.

Why co-buying is rising with affordability pressure

The squeeze is structural, not a blip. With values having outpaced wages for years, the deposit hurdle alone keeps single buyers waiting, and pooling resources is one of the few moves that meaningfully shortens that timeline.

Co-buying is not the only response to the affordability problem, of course. Some buyers look at shared equity schemes like Help to Buy, where the government takes a stake instead of a friend. Others go down the rentvesting path, buying where they can afford and renting where they want to live. Co-buying sits alongside these as another way to bridge the gap, and the right choice depends on your goals, your tolerance for shared risk, and who you would actually trust on a 30-year loan.

How pooling deposits and incomes lifts borrowing power

The mechanics are straightforward. Two deposits combined clear the 20% threshold faster than one, which can mean avoiding Lenders Mortgage Insurance and reaching a target property sooner. Two incomes assessed together also lift the maximum a lender will advance, opening up suburbs and property types that neither buyer could reach alone.

That extra capacity is the whole point. But it comes attached to a catch that most first-time co-buyers do not see coming, and it is worth understanding before you get excited about the bigger number a broker quotes you.

How to structure ownership: joint tenants vs tenants in common

Before you talk to a lender, you and your co-buyers need to decide how your names sit on the title. In Australia there are two ways to hold property with someone else: as joint tenants or as tenants in common. The joint tenants vs tenants in common decision shapes what share you own, what happens when one of you dies, and how easily you can sell your slice. Get it wrong and you can lock yourself into an outcome you never intended.

Joint tenants vs tenants in common at a glance:

Joint tenancy: equal shares and right of survivorship

Under joint tenancy, co-owners hold the property together in equal shares. The defining feature is the right of survivorship. As Moneysmart explains, when one joint tenant dies, their interest passes automatically to the surviving owner or owners, regardless of what their will says.

That suits a couple who genuinely want the survivor to keep the lot. It is usually a poor fit for friends or siblings. If you put in 70% of the deposit and your co-buyer puts in 30%, joint tenancy still treats you as equal owners, and if you die, your family inherits nothing of the property. For most non-couple arrangements, that is exactly the wrong result.

Tenants in common: defined, unequal shares and willing your share

Tenants in common is the structure most co-buyers who are not a couple should look at first. You can hold defined, potentially unequal shares that reflect what each person actually contributed, so a 60/40 or 90/10 split is recorded on the title. There is no automatic survivorship. Each owner can leave their share to anyone they choose in their will.

That flexibility is the point. If three friends buy together and one wants to leave their share to a partner or a sibling, tenants in common lets them. It also matches the reality that people rarely put in identical amounts. The trade-off is that you must be deliberate about your will, because your share will not simply default to your co-owners.

The lending gotcha: joint and several liability when co-buying

Now the part nobody puts on the brochure. When you take out a loan with co-buyers, the bank does not see your share. It sees the whole debt, and it holds each of you responsible for all of it.

Lenders generally treat co-borrowers as jointly and severally liable. In plain English, every borrower can be chased for 100% of the loan, not just their portion. ASIC's Moneysmart spells this out clearly: if your co-buyer stops paying, the bank can come after you for the full amount. Owning only a part of the property does not limit your liability for the debt.

Why the whole debt can count against your future borrowing capacity

The sting goes further than the property you buy together. When you later apply for another loan, perhaps to buy your own home, lenders will often count the entire co-bought debt against your borrowing capacity, not just your share. On paper you can look like you owe the full balance, which can shrink what you are able to borrow next time.

There is an important nuance here. Policies vary between lenders. Some apply debt-apportioning rules that count only your proportionate share of a joint debt when assessing future borrowing, which can soften the impact considerably. Full-debt liability is the general rule, but it is not universal, so this is exactly the kind of question worth putting to a broker before you commit. You can compare mortgage brokers on PropertyGo to find someone who can model how a joint loan affects each co-buyer's future plans, because the difference between a lender that apportions and one that does not can decide whether you can buy again at all.

The co-ownership agreement every co-buyer needs

If you take one thing from this article, make it this: a written co-ownership agreement is not optional. It is the document that protects the friendship as much as the finances. Drawn up properly, it turns vague good intentions into clear, enforceable terms, so that when life throws a curveball, nobody is arguing about what was meant.

Moneysmart's guidance is unambiguous on what the agreement should spell out, and our own analysis at PropertyGo backs this up after seeing how arrangements come unstuck. The agreement should cover the deposit split, who pays what share of repayments and ongoing costs, and a clear plan for every scenario where someone leaves the arrangement.

Deposit split, repayments, ongoing costs and default scenarios

Get specific. The agreement should record:

• The deposit split: Exactly how much each person contributed, in dollars, and how that maps to their ownership share on the title.
• Repayments and ongoing costs: Who pays what proportion of the mortgage, rates, insurance, strata levies, maintenance and repairs. Spell out how this is reviewed if someone's income changes.
• Default scenarios: What happens if one person cannot pay their share. Can the others cover it temporarily and recover it later? Does missed payment trigger a forced sale or a buyout? This is the clause that saves friendships.
• Major decisions: How you decide on renovations, refinancing, or putting the property up for rent. Set a threshold above which everyone must agree.
• Dispute resolution: A clear process, such as mediation, before anyone reaches for a lawyer.

A property purchase is a big enough financial commitment that getting the supporting team right matters too. If you are buying together and want an expert in your corner during the search and negotiation, you can find a buyer's agent through GoMatch to keep the purchase itself on track while your agreement handles the partnership.

Planning your exit before you buy

It feels strange to plan the ending before the beginning, but exit planning is where co-buying succeeds or fails. People's lives change. Someone gets a job interstate, gets married, has a falling-out, or simply wants their money back. If you have agreed the rules of leaving while everyone is still friendly, those changes become logistics rather than disasters.

Your agreement should map out every realistic exit:

• Sale: If one owner wants to sell and the others do not, what happens? Set a notice period and decide whether the remaining owners get first right to buy.
• Death: Make sure your ownership structure and your will line up. Under tenants in common, your share goes to your estate, so the others may suddenly have a new co-owner they have never met.
• Default: Define what counts as default and what the consequences are, including whether the others can buy out a defaulting owner.
• Buyout: Agree the process for one owner buying out another, including timeframes and how the price is set.
• Valuation: This is the one people forget. Decide upfront how the property is valued on exit, for example two independent valuations averaged, so nobody can argue the price is unfair years later.

Settle these on paper now and you remove the two biggest sources of co-ownership disputes: money and surprise.

First home buyer grants and stamp duty: how co-buying can affect eligibility

Here is a trap that can quietly cost you tens of thousands. If you co-buy with someone who already owns property, you can reduce or even lose your eligibility for first home buyer grants and stamp duty concessions. The schemes are generally designed for genuine first-time buyers, and adding a current owner to the contract can disqualify the whole purchase from a concession you assumed was locked in.

The rules differ by state and territory, and they move. A concession that exists today may be tightened or withdrawn at the next state budget, and the value thresholds shift from one jurisdiction to the next. So treat nothing you read online as gospel when real money is on the line.

Confirm the current rules directly with your own state or territory revenue office (the SRO in Victoria, Revenue NSW, the QRO in Queensland, RevenueSA, RevenueWA and their equivalents) before you sign anything. The few minutes that takes can be worth a five-figure saving, or save you from banking on a concession you were never entitled to.

This is general information, not financial, legal or tax advice, and you should consult a licensed professional about your own circumstances.

Getting professional advice: legal, conveyancing and finance

Co-buying touches property law, lending, tax and estate planning all at once, which is more than any handshake should carry. Moneysmart strongly recommends independent legal advice and a conveyancer for anyone buying with others, and there is a subtle but important point in the word "independent".

Each co-buyer should ideally get their own separate advice rather than sharing a single adviser. One lawyer cannot fully represent two people whose interests might diverge, especially around who gets what if the arrangement ends. Paying for two lots of advice feels like a waste right up until the moment it is not. The roles worth lining up:

• A solicitor or conveyancer for the contract, the title and the ownership structure.
• A solicitor for the co-ownership agreement, ideally separate advice for each party.
• A mortgage broker to structure the loan and model how joint and several liability affects each person's future borrowing.
• An accountant if there are tax or investment angles, particularly for unequal shares or an investment property.

If a buyer's agent is part of your plan, it pays to know what you are signing up for there too. We break the fees down in what a buyer's agent costs so you can budget the whole team, not just the deposit.

FAQ: Co-buying property in Australia

What is co-buying property?

Co-buying is when two or more people buy a property together to combine their deposits and borrowing power. They might be friends, siblings, parents and adult children, or unrelated buyers. It is increasingly common as affordability worsens and single buyers struggle to save a deposit alone.

What is the difference between joint tenants and tenants in common?

Joint tenants hold the property together in equal shares with a right of survivorship, so a deceased owner's share passes automatically to the survivors. Tenants in common can hold defined, unequal shares and each owner can leave their share to anyone in their will. Most non-couple co-buyers are better suited to tenants in common.

Am I responsible for the whole loan or just my share?

Generally the whole loan. Lenders usually treat co-borrowers as jointly and severally liable, so each borrower can be held responsible for 100% of the debt even if they own only part of the property. Some lenders apply debt-apportioning policies for future borrowing, so check with a broker.

Does co-buying affect first home buyer grants?

It can. Buying with someone who already owns property may reduce or remove your eligibility for grants and stamp duty concessions, and the rules differ by state and territory. Always confirm the current position with your state revenue office.

Do I really need a co-ownership agreement?

Yes. A written agreement covering deposit split, repayments, ongoing costs, default, exit and dispute resolution is what protects both your money and the relationship if circumstances change.

The bottom line

Co-buying is a sensible answer to a genuinely hard problem, and for a lot of Australians it is the difference between owning and renting indefinitely. The strategy is sound. What sinks people is treating a 30-year financial partnership as casual when it is one of the largest financial commitments they will ever share with another person.

Choose your ownership structure deliberately and put everything in a written agreement. Remember the bank sees the whole debt, not your slice of it, and sort the exit before you celebrate the entry. Do the unglamorous parts properly and co-buying lets you beat affordability without betting the friendship on it.

Sources

1. ASIC Moneysmart, guidance on buying property with others and co-ownership, 2026
2. ASIC Moneysmart, joint tenants and tenants in common glossary definitions (moneysmart.gov.au), 2026
3. Cotality (formerly CoreLogic), Australian dwelling value and affordability data, 2026
4. State and territory revenue offices (SRO Victoria, Revenue NSW, QRO, RevenueSA, RevenueWA), first home buyer concession and stamp duty rules, 2026
5. PropertyGo analysis of deposit and affordability barriers, 2026