Guarantor loans now underpin more than 60% of first home buyer purchases. How they work, what parents are really pledging, and when the guarantee can be released.
The Bank of Mum and Dad is now, by contribution size, one of the largest sources of first home buyer finance in Australia. Recent industry estimates put the total at around $35 billion a year, and more than 60% of first home buyers now rely on some form of parental support to get into the market. In 2026, mortgage brokers report writing more guarantor loans than they did in the entire four years before that.
Guarantor loans get talked about a lot, and understood a lot less. If your parents are considering standing behind your loan, it is worth both sides knowing exactly what is being offered, what the bank is actually taking as security, and what the plan is for releasing them from the arrangement later.
The mechanics are simpler than the industry language suggests. Your parents use the equity in their own property as additional security for a portion of your loan, usually the portion sitting above 80% of your property value. That reduces the lender's exposure on your side of the deal to 80% LVR, which is the threshold at which Lenders Mortgage Insurance is normally waived.
No cash actually changes hands. Your parents do not deposit money. Their home is listed as security on a portion of your loan, and if you keep meeting your repayments, they may never have to lift a finger beyond signing the paperwork.
A worked example makes the numbers clearer. Say you buy a $700,000 home with a $35,000 deposit, which is a 5% deposit. Without a guarantor, your LVR is 95% and estimated LMI is roughly $24,500, typically capitalised on top of your loan. With a guarantor pledging around $105,000 of their equity as extra security, the lender sees the effective LVR on your property as 80%, and the LMI is waived. The parents' documented exposure is that $105,000 chunk, or until your loan naturally drops below 80% LVR, whichever comes first.
This is where the honest conversation needs to happen. The parents' home is real security. If you fall behind on repayments and the loan goes into default, the lender can pursue their property to recover the shortfall, up to the guaranteed amount.
The stress scenario worth walking through with them is a job loss early in the loan combined with a property downturn. Imagine you lose income in year one, the property falls 10%, and the bank forces a sale. On a $700,000 purchase with a $665,000 loan and a new market value of $630,000, the sale falls short by roughly $35,000 after costs. That gap sits inside your parents' guaranteed portion and can be called upon. It is a real risk, not a theoretical one, and it is why lenders require independent legal advice before signing.
The good news is that the industry standard now is a limited guarantee, capped at the shortfall above 80% LVR. Full guarantees, where the parents stand behind the entire loan, are rare and much riskier. Before anyone signs, confirm in writing which structure your lender is using.
This is one of the most under-discussed parts of the arrangement. Guarantor loans are not meant to be permanent. Once the LVR on your own property drops to 80%, through a combination of your repayments and property growth, your parents can apply to be released from the guarantee.
For a $700,000 property with typical growth around 4% a year and standard principal-and-interest repayments, that release point typically arrives in 4 to 7 years. That range shifts based on how much extra you can repay and how the market moves in your area. Some families accelerate the release by making lump sum payments from bonuses or tax refunds, which is worth modelling before you sign.
The application to release the guarantee is not automatic. You need to formally request it, provide a current valuation, and have the lender agree. Diarising a check every year around the anniversary of the loan is a habit worth building so the guarantee does not sit there longer than it needs to.
Guarantor structures are one of three ways parents commonly help. It helps to be clear on the differences before choosing.
Before committing to a family arrangement, it is worth checking whether a government scheme covers the same gap. The federal First Home Guarantee lets eligible buyers purchase with a 5% deposit without paying LMI, at no cost or risk to family. The Help to Buy shared equity scheme lets eligible buyers purchase with a 2% deposit and no LMI, in exchange for a government equity share. Neither involves your parents' property.
If you qualify for a scheme that closes the LMI gap on its own, the case for exposing a parent's home to a guarantee weakens considerably. Working through both paths with real numbers is the best way to see which one leaves the family better off overall.
A guarantor loan can be genuinely powerful, but the family conversation matters more than the paperwork.
Use these tools to see how the guarantor path compares with the alternatives for your situation. This article is general information, not personal advice, and your lender or a licensed professional can walk through your specific position.