Does a Guarantor Increase Your Borrowing Power? The Honest Answer

“I’ll Go Guarantor if It Helps”

Andrew’s* dad made the offer over a family dinner, the way thousands of Australian parents do: “I’ll go guarantor if it helps.”

So Andrew asked us: would it?

Our answer surprised him: not in the way he expected. A guarantor wouldn’t solve his income-based serviceability limit — and in his case, it wouldn’t even save him money, because his loan structure had already dealt with mortgage insurance. Putting his dad on the hook would have delivered precisely zero benefit. As our broker put it on the call: “It doesn’t solve your serviceability, it can help with security and may help avoid mortgage insurance… it’s probably more detrimental to get dad involved, in my opinion.”

*Names changed. The client conversations quoted on this page are real Hunter Galloway calls, anonymised.

We talk clients out of guarantor loans regularly. We also set them up every week, because for the right situation they’re brilliant — higher-LVR lending and potentially reduced LMI, into the market years earlier. The difference between those two outcomes is understanding what a guarantor actually changes. Most websites won’t tell you plainly, so here it is. (This guide is part of our complete guarantor home loan guide.)

The One-Sentence Rule

A guarantor replaces your deposit, not your income.

Your borrowing power — the maximum loan a bank will approve — is set by your income, your debts, your expenses and your dependants, stress-tested at a buffered rate about 3% above your actual rate. A guarantor changes none of those inputs. What a guarantor changes is the security behind the loan: their property equity stands in for the deposit you haven’t saved.

We’ve watched this land as genuinely unwelcome news on real calls. One client was pre-approved at $700,000 and chasing a $1.25 million property, hoping a guarantor would bridge the gap. It can’t — not that gap. A guarantor could take her to roughly $900,000 by removing the deposit constraint and LMI, but no guarantee on earth makes a bank ignore what your income can service. Another client heard it in one line from our broker: “Even if your parents had $200,000 of equity available to you, your loan maximum still could only be $720,000.”

What a Guarantor Actually Changes

Three things, and they’re significant:

1. Your deposit requirement may drop substantially. With a guarantor’s equity as additional security, some lenders may fund the purchase price plus certain eligible costs. The exact LVR, costs covered and deposit-source rules vary by lender, and you still need to meet serviceability requirements.

2. LMI may reduce or disappear. Lenders mortgage insurance often applies above 80% LVR, but a suitable guarantee may reduce or avoid it depending on the lender and guarantee structure. Use our LMI calculator to see what that’s worth at your price point.

3. Years of saving disappear. This is the real prize. If saving a deposit would take you four years while prices move away from you, a guarantor collapses that time to zero. Whether that’s worth the family risk is exactly the calculation to make deliberately — not at a family dinner.

So When Does a Guarantor Change the Outcome — and When Doesn’t It?

A guarantor is genuinely powerful when:

• Your income comfortably services the loan you need, but the deposit is the blocker — the classic strong-income/no-savings first home buyer.
• You’re buying above the 5% Deposit Scheme price caps, or buying an investment property (the scheme is owner-occupier only). (Full comparison here.)
• You need eligible purchase costs considered within the loan — where the lender permits it.
• You have less than 5% saved and the alternative is years of rent — see our guide to no deposit home loans.

A guarantor adds risk for little or nothing when:

• The real constraint is your borrowing power. No guarantee fixes servicing. (The fixes that do: clearing debts — we’ve seen a single unused $5,000 credit card cost $20,000 of capacity — adding income, or adjusting the target price.)
• You already qualify for the 5% Deposit Scheme at your price point and you’re an owner-occupier — near-identical outcome, zero liability on your parents.
• Your loan is already structured under 80% LVR — as Andrew’s was. The LMI saving is the main event, and there’s nothing left to save.

That second list is the part most guarantor pages won’t publish, because it talks people out of loans. We’d rather you trust the first list because we were honest about the second.

If the Answer Is “It Helps” — What Your Parents Are Signing Up For

Keep this short here, because we’ve written a full parent-facing guide: the guarantee is may be limited(the exact liability is defined by the guarantee contract), they’ll need independent legal advice, and the exit should be planned from day one — most guarantees may be released after the lender assesses the request, which can involve LVR, valuation, repayment conduct and whether the borrower can stand alone. Hand them the guide before anyone signs anything. And if a guarantor isn’t the right tool, there are four other ways family can help — gift, co-borrowing, property share and shared equity.

The Honest Assessment, Free

The guarantor conversation involves your family’s home, so it deserves a straight answer before anyone signs: will it actually change your outcome, or just add risk? We’ll run your numbers both ways — with the guarantee, and under the 5% Deposit Scheme — and show you the difference in dollars. If the answer is “don’t involve your parents,” we’ll tell you that too. We have before.

Call 1300 088 065 or book a free assessment.

Lender policies on guarantor lending — maximum LVRs, genuine savings requirements and guarantee structures — differ between lenders and change without notice. Policies as at July 2026. This guide is general information, not credit advice; your full situation needs to be assessed before any recommendation.