An interest-only investment loan in Australia is a loan where the borrower pays only the interest each month for a defined period — typically 1–5 years — with the principal repaid at the end of the IO period (usually via a switch to principal & interest, refinance, or sale). For investment property borrowers, IO loans have been a common structure for decades, driven by both cashflow management and Australian interest deductibility rules.
APRA's macroprudential settings tightened sharply on IO investment lending between 2014 and 2018, reshaping bank appetite. This guide explains where IO investment lending sits in 2026, what the banks will and won't do, and where private lenders fit on the files banks decline.
Why investors use IO loans
- Cashflow management. Monthly repayments are materially lower than P&I on the same loan — typically 30– 40% lower in early years. For investors holding multiple properties with negative gearing, IO repayments improve net cashflow during the holding period.
- Interest deductibility. Under Australian tax law, interest on a loan used to acquire an income-producing asset is generally deductible against the income. Principal repayments are not deductible. IO repayments are 100% interest, maximising the deductible expense.
- Portfolio strategy. Investors holding for capital growth rather than current income often prefer IO during the growth phase, switching to P&I or selling before the IO period ends.
The tax efficiency assumption depends on the investor's circumstances. Archer Wealth does not provide tax advice; consult a registered tax agent.
APRA's impact on IO investment lending
Between 2014 and 2018, APRA imposed two macroprudential interventions that materially changed the IO investment market:
- 2014: 10% growth cap on investor lending. APRA capped each ADI's growth in investor lending at 10% per year, forcing banks to ration investor loan approvals.
- 2017: 30% IO cap. APRA limited new IO loans to 30% of each bank's new mortgage flow, plus tightened serviceability buffers on IO loans (assessing IO loans on a P&I basis at the end of the IO period).
The 2017 IO cap was eased in 2018 but the underlying serviceability assessment changes remained. Major Australian banks continue to write IO investment loans, but inside a materially tighter envelope than pre-2014.
Bank IO investment policy in 2026
- Maximum IO term. Standard 5 years; some major banks allow up to 10 years on investment IO. At end-of-IO, the loan converts to P&I over the residual term unless extended.
- Maximum LVR. Typically 80% on IO investment (with LMI); 70% without LMI.
- Serviceability assessment. The bank assesses IO investment loans on a P&I basis at the end of the IO period, plus a 3% buffer above the actual rate. So a 6% actual rate IO loan for 5 years on a 30-year amortisation is assessed at 9% P&I on a 25-year amortisation. Borrowing capacity is materially lower than the headline rate suggests.
- Pricing premium. Investment IO rates typically sit 0.15–0.35% above investment P&I, which itself sits 0.15–0.45% above owner-occupier P&I.
Where bank IO investment hits a wall
- Portfolio investors. The bank's assessment-rate buffer compounds across multiple properties. An investor with 4–6 investment properties hits the soft DTI cap of 6× total liabilities to gross income before serviceability fails — even where rental cashflow comfortably services the actual rates.
- Long-tenor IO. Banks generally cap IO at 5 years; some sophisticated investors want 7–10 year IO structures aligned to a longer-term hold strategy.
- IO during establishment. A recently-acquired property with a stabilising tenant or a build-to-rent style asset may not produce the cashflow needed to service P&I from day one. Bank policy doesn't typically accommodate extended IO for stabilisation.
- Self-employed and complex structures. The bank IO serviceability test compounds the complexity faced by self-employed investors — see the low doc guide.
Where private lenders write IO investment
Private lenders write IO investment files outside bank policy when the credit makes sense on commercial-reality basis:
- Portfolio top-up IO. A first mortgage on a new investment acquisition where the borrower's overall portfolio cashflow services comfortably, even though the bank buffer model fails. Typical 12–24 month tenor, IO throughout, refinance exit to major bank at the file's 24-month mark.
- Stabilisation IO. A recently-acquired commercial or mixed-use property where rental income is building over the first 12–18 months. IO during stabilisation, switch or refinance to long-tenor finance at full stabilised value.
- Bridging investor-to-investor IO. Bridging on an investor's portfolio between sale of one investment property and acquisition of another. IO with capitalised interest is the standard structure.
Pricing on private IO investment in 2026 sits 7.85–10.5% per annum depending on file profile, LVR, security type, and exit quality.
End of IO: the planning question
Every IO investment file has a question that needs to be answered at submission: what happens at end of IO? Three answers:
- Switch to P&I with the same lender. Requires re-serviceability assessment at the time of switch. If serviceability is tighter or rates have moved, the switch may not be possible.
- Refinance to a new IO term. Common but not guaranteed — bank IO appetite can tighten between origination and end-of-IO. Borrowers who plan to roll IO forward should have backup lenders identified.
- Sell the property. The cleanest exit if capital growth has materialised. The end-of-IO trigger can force a sale at the worst time if market timing is poor.
The right pattern is to plan the end-of-IO outcome at submission, not in year 4 of a 5-year IO term. Brokers who've seen IO rollovers fail will tend to write IO files with a documented end-of-IO plan included in the file note.
How files run at Archer
Archer Wealth writes IO investment files through Archer Edge (residential investment) and Archer CommercialX (commercial investment). Tenors 12–36 months, IO with capitalised or serviced interest depending on file structure, LVR to 75% on metro residential investment and 70% on investment-grade commercial. Indicative same-day, formal within 5 days, settlement typically 7–14 days from formal.