I understand this topic has been discussed a number of times in here, and I have gone through the fantastic tips and replies on this. But still not 100% sure about situations where there is extra cash in hand and what to do about it with IP offset accounts. Scenario: PPOR : Loan A: 320K OO loan with IO, offset A with 320K, so paying no non-deductible interest. PPOR equity: Loan B: split 32K IP loan with IO, just approved and the bank put the 32K into its corresponding offset B. IP (worth 350K): Loan C: 350K * 80% = 280K. Remaining 20% deposit = 70K. Say I have got 70K cash in hand, does it make a difference if I use all my cash for the deposit, or to exhaust loan B of 32K (or more accurately, offset B) plus cash in hand of 38K? This seems really confusing to me. A moment ago I thought I understood it clearly, the next minute I am confused again. The ideas I received from other posts are: 1: Use borrowed money to invest to allow for tax benefits 2: Don't use cash to invest 3: Don't use offset account to invest cause its equivalent to cash Is there a way to maximise both cash flow and tax deduction at the same time?