I would like to confirm whether these tax deduction rules also apply to investments in shares.
For example, Mr. X and Ms. Y have a joint loan secured against their owner-occupied residential property, established on 1 July 2024, with the following structure:
- $350,000 allocated to their owner-occupied home at an interest rate of 5.5%; and
- $234,000 allocated for investment purposes at an interest rate of 6%.
If Mr. X uses the $234,000 investment portion of the loan to invest in the stock market on 1 July 2024, can he claim a 100% tax deduction on the interest associated with this investment loan at his marginal tax rate (e.g., 30%)?
Specifically, would Mr. X be able to claim a tax deduction of:
$234,000 × 6% × 30%
for the full financial year ending 30 June 2025, assuming:
- The investment is held for the entire year;
- There are no changes to the interest rate or Mr. X’s marginal tax rate.
Additionally, assuming Mr. X sells all his shares on 31 December 2025 (1.5 years after purchase) and realises a capital gain of $16,000, would the following tax treatment be correct?
- For the relevant financial year, he claims an interest deduction of:
- $234,000 × 6% × 30%
- For the capital gain, he applies the 50% CGT discount (since the shares were held for more than 12 months), resulting in tax payable of:
- $16,000 × 50% × 30%
Would this calculation be correct, and is Mr. X eligible for the 50% capital gains tax discount after holding the shares for more than one year?
Author: NikkiATO(Community Moderator)Community Moderator 28 May 2025
Hi @KTaxPro,
We can’t confirm calculations or give personal tax advice, but we can definitely point you in the right direction.
Yep, if Mr. X borrows money to buy shares and it’s reasonable to expect he’ll earn income (like dividends), then he can usually claim a deduction for the interest on that part of the loan. Even if the loan is split with a private portion (like a home loan). But he can only claim the interest on the investment portion.
Sounds like Mr. X held the shares for more than 12 months before selling. So yes, he may be eligible for the 50% CGT discount, as long as he’s an Australian resident for tax purposes.
If the loan is in joint names, each person can only claim their share of the interest. Usually, 50/50 unless there’s a different ownership split.