Buying an investment property with a partner, sibling or friend is fast becoming a mainstream way to break into the property market. House prices in Australia are among the highest in the world, and NAB reported a 33% jump in joint home loans between friends and family from August 2024 to July 2025. The deposit gets split, the loan gets approved, and everyone is optimistic.
If you are buying an investment property with a partner in Australia, the loan is the easy part. What catches co-buyers out is everything wrapped around it: how you hold the property, who the tax office treats as owning what, and who owes the bank if the other person stops paying. None of it is hard to sort out. All of it is much harder to sort out after you have signed.
Here is what to settle before you sign anything.
Joint tenants or tenants in common
Australian co-owned property is generally held in one of two ways, and the choice decides what happens if an owner dies, sells, or runs into financial difficulty.
Joint tenants own the property together as a single legal interest, in equal shares. Neither of you can sell a share independently, and if one of you dies, the share passes automatically to the surviving owner. That is the right of survivorship, and it means the deceased's share never becomes part of their estate. Couples buying a family home commonly choose this structure. It tends to fit badly where an owner wants to leave their share to someone else, or in blended families.
Tenants in common means each of you holds a separate legal share, and the shares do not have to be the same size. One of you can hold 80% while the other holds 20%. Each owner can sell, mortgage or lease their share without the others' agreement, and leave it to anyone they choose. There is no survivorship: when a tenant in common dies, their share becomes an asset of their estate and goes wherever the will sends it. In the ATO's example, Anita and Noor bought as tenants in common with Anita holding 80%, and when Anita died her share passed to her son under her will.
| Joint tenants | Tenants in common | |
|---|---|---|
| Shares | Equal | Can be unequal, e.g. 80/20 |
| Selling your share | Not independently | Yes, without the others' agreement |
| If an owner dies | Share passes to the survivor | Share becomes part of the estate |
For an investment property, especially one where the contributions are unequal, tenants in common is the structure typically used.
The loan binds you both
Two things about co-borrowing are better known before approval day than after.
First, liability. Hudson Financial Planning notes that most lenders treat co-borrowers as jointly and severally liable, meaning each party is responsible for the entire debt. If your co-owner stops paying, the lender comes to you for all of it.
Second, your next loan. Hudson Financial Planning notes that even if you only own 50% of a property, banks often count 100% of the loan against your borrowing capacity. If buying solo one day is part of the plan, run that maths now.
The debt itself deserves a stress test. Borrowing to invest is a medium to long term strategy, at least five to ten years. On top of the interest you will pay council rates, insurance and repairs. If interest rates rose 2% or 4%, could you both still afford the repayments? And if your own home is up as security for the loan, know that a loan you cannot service puts the house you live in at risk.
The tax office follows the title, not the loan
Rental income and expenses must be divided among co-owners according to their legal interest in the property, and generally only someone named on the title can declare the income and claim the expenses.
That produces a trap couples walk into. Say you put the property in one partner's name for tax reasons, but the mortgage stays in joint names because neither of you could service it alone. The partner off the title cannot claim the interest, even though the loan is in their name too. Where both incomes are needed to service the debt, the cleaner setup is a loan in the owner's name alone, with the other partner as guarantor. Which bank account the rent lands in does not change any of this.
What the bank calls the product matters less than what you do with the money. Interest may be deductible where the borrowed funds bought a property that is genuinely available for rent, even if the loan is labelled owner-occupier rather than investment. Keep records showing where the money went.
One date to check before you run the numbers: the 2026 Federal Budget, delivered on 12 May 2026, announced changes to the application of negative gearing. Confirm the current position with the ATO before you commit.
The co-ownership agreement
A co-ownership agreement is a legally binding contract between the owners. It sets out how you will manage the property and what happens if disputes arise. Put one in place whichever ownership structure you choose.
Understand what it cannot do: co-ownership does not shield the property from creditors. A court can sever a joint tenancy and force the sale of a debtor's share.
Get legal advice before you sign a contract for sale or settle the ownership structure, so you know the long-term consequences of both.
The decision that is left: where to buy
Structure, loan and agreement settle the partnership. They do not tell you where to buy, and that is the argument co-buyers actually have, because each of you arrives with a different hunch about the market.
This is where we come in. PropSpotter is a three-stage system: research, sourcing and coaching. The research stage draws on more than 30 data sources, from ABS census figures at SA1 level to supply and demand indicators, rental yields, infrastructure pipelines and growth modelling, delivered as a single research brief. Both of you read the same brief, so you are weighing the same numbers instead of trading gut feelings. The sourcing engine then watches your target suburbs around the clock and flags listings the moment they go live, with automatic screening for bushfire risk, public housing density and owner-occupier ratio. And one-on-one coaching from an active investor runs through the whole purchase, reviewing your shortlist and helping you negotiate.
The whole system is a fixed $4,990. There is no percentage-based fee that grows with the purchase price, so it costs the same whether you are buying at $500K or $1.2M. If the alternative on your table is a buyer's agent, those typically run $15,000 to $30,000+, or about 2% of the purchase price, and the model is done-for-you rather than done-with-you. The difference shows up on your second purchase: after one cycle through the system you have the framework, the data literacy and the negotiation experience to run the next one yourself. The research covers suburbs Australia-wide, so it suits investors outside Sydney and Melbourne as much as those inside them. More than 100 investors have been coached through the system, and every one of them has rated it five stars on Google.