Once all the income items have been completed it's time to get to work on itemising my deductions. The biggest one for me is the interest paid on the margin loans I've used to buy stocks for my share portfolio. I pay some interest up to 12 months in advance (in late June) to bring forward the tax deduction, and the remaining interest component is part each month as it accrues. My overall gearing level is fairly modest - around 50% loan-to-value ration (LVR), which corresponds to a debt:equity ratio of 1:1. As the interest paid on the margin loan is more than the dividends received, I get a net income tax deduction from my stock portfolio. Eventually capital gains tax will be paid on realised gains when stocks are sold, but, provided they've been held for more than 12 months before being sold, the capital gains tax rate is effectively half my marginal income tax rate (the actual calculation is to apply my marginal tax rate to 50% of capital gains).