Sorry Nitrogen. I didn't read your question properly. That's why it's never wise to act solely on advice from social media forums. If your tax consultant is worth anything they should know ...... particularly as the question is a common one and the ATO web site is only one mouse click away.
As a general rule, home office expenses (pro rated telephone, internet and other expenses) can only be claimed FOR BUSINESS. That includes stuff you may do for your day job at home (read and write reports etc). Part time investors may not make the cut so as to be defined as a business.
There are reasons why you may not want to be considered a "trader". Traders don't necessarily get the 50% CGT discount that "investors" are entitled to. Subject to advice from a proper tax consultant, it may be possible to keep an investment portfolio and a trading portfolio separate. But you describe yourself as an investor rather than a trader.
