Borrowing may become more attractive if you can claim the cost of borrowing (the interest) as a tax deduction. This helps you to recover some of the costs through paying lower tax. However, the interest incurred on a mortgage to buy your private residence (home) is not tax deductible when used for personal purposes.
Borrowing to purchase an income-producing investment (e.g. investment property or shares) will normally result in the interest being tax deductible. Generally speaking, the interest will be deductible against the income that you are receiving from the investment. It is important to speak to your accountant or refer to the ATO website to determine if your loan interest is deductible.
Tax deductibility may get complicated when you use the equity in your home to borrow to purchase an investment.
Using a separate loan account, which is only used for investing, helps to keep the interest costs separate. And all of the interest on the investment loan account is likely to be deductible. Otherwise, keep good and clear records.