Quick answer: Bridging finance allows an eligible homeowner to buy another property before the existing property sells. The useful question is not just what interest rate will I pay? It is how much debt peaks during the overlap, how much remains after sale, and what happens if the sale is delayed or discounted.
First, distinguish the three debt figures
A bridging proposal often involves three different amounts:
| Term | What it means | Why it matters |
|---|---|---|
| Existing debt | The mortgage still outstanding on the current home | Has to be repaid or incorporated in the transaction |
| Peak debt | Total borrowing required during the period when both properties are held | Drives lender security assessment and bridging-period finance cost |
| End debt | Mortgage left after net proceeds from the old property are applied | Must be manageable after the bridge ends |
For an illustrative calculation, peak debt ≈ current mortgage + new purchase price + buying costs − cash contributed. Then end debt ≈ peak debt + any capitalised bridging interest − net sale proceeds. This is a financing worksheet, not a universal lender formula: the loan and settlement structure can shift individual amounts.
The interest rate matters, but a borrower with $1.7 million of peak debt can incur a large dollar cost even if they intend to end with a much smaller loan.
Worked example: upgrading from a $1 million home to a $1.3 million home
Assume the following hypothetical scenario:
| Item | Amount |
|---|---|
| Current home's estimated sale price | $1,000,000 |
| Current mortgage balance | $350,000 |
| Replacement home's purchase price | $1,300,000 |
| New purchase costs (illustrative) | $70,000 |
| Extra cash available toward settlement | $0 |
| Selling costs (illustrative) | $30,000 |
Before interest and any specific lender adjustments:
Peak debt = $350,000 + $1,300,000 + $70,000 = $1,720,000.
Net sale proceeds = $1,000,000 − $30,000 = $970,000.
End debt = $1,720,000 − $970,000 = $750,000.
That end debt is the economically important long-term figure. The borrower still has to establish that the lender will support the much larger peak debt, its security structure and its bridging terms.
What if the sale takes three months?
At an illustrative constant 8% annual rate applied to the full $1.72 million for 90 days, simple interest would be approximately $33,929 ($1,720,000 × 8% × 90/365). If all that amount were added to the facility, an illustrative end debt would increase to around $783,929, before any additional charges. In reality, a lender might charge different rates on loan portions, require interest-only payments, or capitalise interest according to its terms.
What if the old property sells for $900,000 rather than $1 million?
Holding the $30,000 assumed sale cost constant, net sale proceeds become $870,000. End debt before bridging interest then rises to $850,000—$100,000 more than the original estimate.
What if sale is delayed and the price disappoints?
Both effects can operate simultaneously: interest continues during the overlap and a lower sale price reduces the amount available to repay peak debt. Stress-test price, time and settlement costs separately rather than relying on the most optimistic combination.
How different bridging structures work
Interest-only during the bridge. A lender may require interest to be paid during the overlap while the existing property is being marketed. For example, Commonwealth Bank describes an interest-only arrangement during its bridging period and a maximum 12-month term for its product. These are that lender's published terms, not a statement about the whole Australian market.
Capitalised interest. Some structures allow interest to be added to the outstanding debt temporarily. This reduces immediate cash repayments, but increases the amount owing and can tighten the eventual end-debt position. Availability and security treatment vary by product.
No end debt / downsizing. If the sale proceeds should extinguish the entire financing, the borrower may be seeking a short-term bridge without a continuing mortgage. This can be a materially different lender/product decision from a bridge that transitions into a long-term home loan.
Overlap after contracts are exchanged. A short bridging period can be used where both properties are contracted but settlement dates do not align, reducing the need for storage, temporary accommodation or simultaneous removals. Fees may still make even a brief bridge expensive.
The key timing decisions
Buy before selling
This may secure the property you want and avoid renting or moving twice. It also exposes you to sale-timing and price uncertainty while two properties are held.
Sell before buying
This gives certainty around available equity and reduces bridging exposure, but may require temporary accommodation or mean purchasing under time pressure after sale.
Negotiate longer or aligned settlements
A longer settlement on the purchase, or a negotiated period between the two settlements, can reduce how long the bridge is outstanding. However, settlement timing is negotiated with counterparties and is not always under your control.
Sell subject to settlement or make a conditional offer
Conditional contracts or negotiated settlement terms might reduce the funding gap, but sellers may prefer a competing unconditional buyer. Compare the commercial trade-off rather than assuming a financing structure alone determines whether the transaction is viable.
Seven borrower questions worth answering before committing
1. Is the quoted rate charged on peak debt or just the new-home portion?
Ask the lender for a schedule specifying each outstanding portion, interest rate, payment method and period. A rate percentage alone does not show the dollar cost.
2. How much could I still owe after my old place sells?
Start with a conservative net sale figure after agent and selling costs, then add acquisition costs, all bridging fees and the interest treatment to calculate end debt.
3. How long do I have to sell?
There is no single term for all bridging products. Commonwealth Bank currently publishes a maximum term of 12 months for its product. Confirm the exact term of the offer you're considering, including what happens at expiry.
4. Can I avoid making repayments while holding both homes?
Not always. Some arrangements require interest-only repayments; others permit capitalisation. Compare the effect on available cash and the final debt.
5. What if the sale appraisal is optimistic?
Test a 5%, 10% or 15% lower net sale result and recalculate end debt. Also ask which valuation the proposed lender will use.
6. What if I already signed the purchase contract?
Work backwards from the contractual settlement date. Establish whether financing, loan approval, property security and selling arrangements can realistically be put in place before settlement.
7. Does a near-zero end debt mean the lender will automatically approve the bridge?
No. The lender still has to assess the financing structure, repayment arrangements, security, risks and exit. A small projected end debt is not the same as a guaranteed approval.
What Australians are asking in practice
The questions above reflect concerns seen in Australian discussions, not verified lender rules. In an April 2026 AusFinance discussion, borrowers debated whether short settlement overlap could justify bridging interest compared with the disruption of simultaneous moves. Another March 2026 discussion focused on capitalised interest, peak debt and the number of months needed to sell. In a June 2026 property discussion, participants disagreed over buy-first risk versus the convenience of a planned sale.
The commercially useful lesson: calculate the worst plausible end-debt outcome, not just the best-case overlap cost.
A worksheet to take to your lender or broker
Prepare the current property's mortgage payout figure and conservative sale-price range; estimated sale costs; replacement property price and deposit already paid; purchase duty and settlement costs; realistic sale and purchase settlement dates; savings available; and the amount of continuing mortgage debt that you can comfortably service after the sale.
For the non-bridging components, use GPS Finance's Deposit & Buying Costs Calculator, Mortgage Repayment Calculator and Borrowing Power Calculator. These are not bridging-loan calculators; they answer the component questions without inventing lender-specific bridge mechanics.
If you're weighing buying first, selling first or a staggered settlement, discuss the mortgage funding structure. Include estimated sale value, existing mortgage, new property price and both settlement dates in your enquiry.
Sources and verification
- Commonwealth Bank — Bridging Loan: lender-specific definition, interest-only repayment structure and published term.
- ASIC Moneysmart — Buying a house: acquisition costs, borrowing considerations, pre-approval and settlement planning.
- ASIC Moneysmart — Choosing a home loan: questions about features, rates and costs.
- Australian forum discussions linked above provide borrower-question context only.
About the author: Krish Neelamraju is a finance and credit professional and founder of GPS Finance Group.
Need help matching this to a business-finance option?
GPS Finance can review the funding purpose, conduct, documents and lender fit before you make a formal enquiry.
