Interest-Only Home Loans Australia

An interest-only (IO) home loan is a loan where, during a set period, your repayments cover only the interest charges — not the principal (the amount you actually borrowed). Once the interest-only period ends, your loan reverts to principal and interest (P&I) repayments, and your monthly payments increase. This loan structure is widely used by property investors to maximise cash flow and tax efficiency.

How Interest-Only Home Loans Work

Under an interest-only loan, your monthly repayment is calculated as:

Monthly repayment = (Loan balance × Annual interest rate) ÷ 12

For example, on a $700,000 IO loan at 6.5% per annum, the monthly repayment is $3,792 — compared to approximately $4,421/month for a P&I loan over 30 years at the same rate. The IO loan saves $629/month during the IO period, but the total loan amount does not reduce.

Interest-Only Period: How Long Can You Fix It?

Most Australian lenders offer interest-only periods of:

Owner-occupiers: Up to 5 years IO
Investors: Up to 5 years IO (some lenders offer up to 10 years for investment loans)

After the IO period, the loan automatically reverts to P&I repayments over the remaining loan term. Because the principal hasn’t been reduced, P&I repayments are calculated on the original loan amount over a shorter remaining term — resulting in a significant payment “step-up” that must be planned for.

What Happens When the IO Period Ends?

This is where many borrowers are caught off guard. When your IO period expires, your repayments jump to include principal repayment. Using the same $700,000 example at 6.5%:

During 5-year IO period: $3,792/month
After IO expires (P&I over remaining 25 years): $4,717/month — an increase of $925/month

At this point, your options include:

Accept the higher P&I repayments
Refinance to a new IO period with the same or a different lender
Sell the property to repay the loan

Planning for the IO expiry — ideally 12+ months in advance — is critical. Lagos Financial can help investment property owners review their loan structure before the expiry date.

When Does Interest-Only Make Sense?

Investors: Maximising Cash Flow and Tax Deductions

Interest-only loans are popular with property investors for several reasons:

Cash flow: Lower monthly repayments free up cash that can be deployed into other investments or offset accounts
Tax deductibility: Interest on investment loans is tax deductible in Australia. With IO loans, the entire repayment is interest — and therefore 100% deductible
Capital growth focus: Investors whose strategy is primarily capital growth (rather than equity building through principal reduction) benefit from keeping capital flexible

When It May Not Be Appropriate

Owner-occupiers with no investment properties — interest is not deductible on a home you live in, so there is no tax benefit
Borrowers who struggle with financial discipline — the lower repayment can mask the lack of equity building
Those within 10 years of retirement who need to be debt-free

APRA Regulations and Tighter IO Lending

The Australian Prudential Regulation Authority (APRA) introduced significant restrictions on interest-only lending in 2017, limiting IO loans to 30% of new residential mortgage flows at major lenders. Although the formal cap was lifted in 2019, lenders remain more cautious with IO loans — applying stricter serviceability assessments and charging higher rates for IO compared to P&I.

The interest rate premium for IO loans is typically 0.1–0.5% above the equivalent P&I rate, depending on the lender. This spread should be factored into any investment cash flow analysis.

Frequently Asked Questions

How long can I get interest-only on a home loan?

Most Australian lenders allow interest-only periods of up to 5 years for both owner-occupiers and investors. Some lenders extend up to 10 years for investment loans. After the IO period ends, the loan automatically reverts to principal and interest repayments. You may be able to refinance to a new IO period, but lenders will reassess your eligibility at that time.

Is interest-only a good strategy for investors?

For property investors, interest-only loans can be a sound strategy when used intentionally. The lower repayments improve cash flow, and because interest on investment loans is tax deductible, the entire IO repayment can offset rental income. However, IO loans don’t build equity through repayments, so investors rely on capital growth to build wealth. IO is best suited to investors with a clear strategy, a well-buffered cash position, and a plan for what happens when the IO period expires.

What happens when my interest-only period ends?

When the IO period expires, your loan automatically converts to principal and interest repayments calculated over the remaining loan term. This increases your monthly repayments — sometimes significantly. You have several options: absorb the higher P&I repayments, refinance to a new IO period (subject to lender approval), or sell the property. It’s important to plan for this transition at least 12 months before the IO expiry date.

Get Expert Advice from Lagos Financial

With close to 20 years of experience and access to 60+ lenders, Victor Lagos and the Lagos Financial team can help you find the right loan for your situation. Book a free assessment or call us to discuss your options.

Our Services

Lagos Financial offers a full range of mortgage broking services:

We serve clients in Sydney, Brisbane, Launceston, and Australia-wide.

About the Author
Victor Lagos is a licensed mortgage broker (ACL 546774) and founder of Lagos Financial, with close to 20 years of finance industry experience since beginning his career at Bluestone Mortgages in 2006. A member of the Finance Brokers Association of Australia (FBAA) since 2015 and the Australian Financial Complaints Authority (AFCA — 98399), Victor helps Australians build wealth through tailored home loan and property investment strategies, working with 60+ lenders nationwide. Last reviewed: March 2026.

Interest-Only Home Loans: Guide for Investors and Owner-Occupiers