The main reason would be for budgeting by segregating money into monies into different buckets. Some like to save 10% of their income each week to build up a holiday fund. Some may want to build up an education buffer, others might want to segregate an inheritance etc. I have seen clients with offset accounts who do this and have been putting the segregated money in low interest savings accounts instead of offsets. This makes them lose interest savings on the home loan. For every $10,000 you have stored elsewhere you are losing about $300 per year in savings. The other is the informal trust argument. Spouse A might own the property with the offset accounts needing to be in their name only. Spouse B might solely use offset 2 to deposit their salary and savings and keep this segregated from Spouse B. It could be formalised with Spouse A declaring they hold that account as trustee for B. This way if Spouse A suddenly dies Spouse B can get their money back if they don’t want it to get via the will of Spouse A. This can also happen where funds are borrowed from parents to save interest. Dad has $100,000 in a savings account earning 0.1% so son borrows from him and gives him 2% with Son saving himself 1% or $1000 per year roughly. It is a good idea to keep these funds segregated so they are not spent and can be given back to dad at short notice – Dad should also be getting legal advice too. Another reason – a misguided one – is that some people like to drawn down part of a loan and segregate it from cash. It might be a good idea where the loan is split but where there is one loan it will have no effect as the segregation has to occur at the loan level too not just in the offset account. Some of the lenders offering multiple offset account son one loans split include AMP, Macquarie, Suncorp.