Hi, I am buying shares thru Commonwealth Securities. To get their cheapest brokerage cost ($19.95 / trade) you need to settle thru a Commonwealth account called a CDIA account (or a couple of other ways, but I am using a CDIA account which is basically just a standard transaction account). So if you buy $10,000 in shares, then you just make sure you have $10,019.95 in the account three days later and Commsec direct debit you. However, I don't have the cash, so I am borrowing the money to buy the shares using a LOC account. So I do my share trade, then transfer the trade value from my LOC account to my CDIA account and then later that night Commsec direct debit my CDIA account. My question to the forum is, does this transfer maintain the tax deductibitlity of the loan from my LOC? I know that if I wrote a cheque and sent it to commsec, or used bpay to pay from my LOC directly to Commsec then the interest in my LOC would be fully tax deductible. However, I am going thru an intermediary account. Does this intermediary account (the CDIA account) break the chain for tax deductibilty purposes and will the ATO therefore consider me to be paying cash to buy the shares rather than borrowing to buy the shares? I can pay by BPAY, but it costs $29.95 per trade for BPAY instead of $19.95. And does anyone know if there a ruling on this on the ATO website? I make sure my CDIA account is alway empty (except just after a trade), and that it isn't used for anthing else other than buying shares.