Rising Mortgage Rates in Australia: What Property Owners Should Know About Tax

Mortgage costs and tax: different questions

Higher interest rates can put pressure on homeowners and property investors. For property investors, the implications extend beyond monthly repayments: refinancing, redraw facilities and offset accounts can also affect the tax treatment of interest expenses.

The RBA cash rate influences mortgage rates, but it is not the rate charged on an individual home loan. This article uses illustrative rates rather than quoting a current loan offer.

1. How rising interest rates affect mortgage costs

Consider an illustrative $600,000 loan with a remaining 25-year term, principal-and-interest repayments and monthly compounding. Assume a constant nominal annual rate, 300 equal end-of-month repayments, no fees and no offset balance.

Actual repayments depend on the balance, remaining term, repayment structure, fees and lender arrangements. Many loans calculate interest daily; this simplified monthly model is not a lender repayment quote.

2. Does refinancing affect interest deductibility?

Refinancing does not automatically make loan interest deductible or non-deductible. For Australian income tax purposes, the use of borrowed funds is generally critical.

Interest on money borrowed to acquire an income-producing rental property may be deductible, subject to the applicable rules. The property generally needs to be rented or genuinely available for rent during the period claimed. Loan principal repayments are not an interest deduction.

Additional borrowing used for private purposes generally does not qualify for a rental interest deduction, even if secured against an investment property. Replacing an existing loan does not erase its private-use history.

3. Offset accounts and redraw: important tax differences

An offset account generally holds savings separately and reduces the balance on which interest is calculated on a linked loan, without directly repaying its principal. A redraw facility allows access to extra repayments previously made against the loan; access depends on the loan terms.

This distinction matters because redrawn funds are treated as a separate borrowing whose use needs to be traced. For example, redrawing money from an investment property loan for a private holiday can create a non-deductible interest component.

Mixed-purpose loans can require ongoing apportionment and careful records. Do not assume an ordinary repayment can be allocated solely to the private portion; the ATO ruling explains the general proportional approach and limited exceptions.

4. What happens when your home becomes a rental property?

Converting a former main residence into a rental property creates additional tax questions. Consider:

• Whether interest on existing borrowing relates to an income-producing purpose.
• The tax implications of earlier redraw transactions.
• Market value when first used to produce income, if the relevant CGT rule applies.
• Main residence exemption considerations and ownership history.
• Evidence supporting rental income and expenses.

The market-value rule is conditional, not an automatic reset whenever a home is rented out. The ATO sets eligibility conditions, including whether a full main residence exemption would have applied immediately before first income-producing use. Continuing main residence treatment may also be relevant.

Treatment depends on ownership, residence and borrowing history, not simply the current property use or loan label.

5. What records should property investors retain?

Keep original loan agreements, refinancing and settlement statements, interest summaries, redraw transaction records, offset statements and evidence showing how borrowed funds were used. Retain relevant purchase, ownership and valuation records for any later CGT calculation.

Clear documentation helps establish the correct treatment when preparing annual returns or reviewing changes in property use.

Property Tax and Accounting Support

YSE Finance provides Australian taxation and accounting services, including investment property tax returns, rental expense reviews and capital gains tax considerations. Understanding the tax consequences of existing borrowing arrangements supports accurate records and reporting obligations.