PLL delisting from ASX, page-4

If you are trading US listed stocks, through an international broker (assuming you're in Australia with your CommSec account) then you will need to complete a W8-BEN for foreign tax status with the US, and submit that form through your broker.

The CDI's that people on the ASX will be given (converted to) for their current PLL shares will be Australian instruments, tradeable on the ASX, meaning you will NOT need an international account, and you will NOT need to fill in a W8-BEN.

Only if you open an international account, and own/trade US listed stocks, will you need that form.

Even then, that form just tells the US broker to not withhold any capital gains tax from sales or dividends, as they come under the Australia/USA double taxation agreement. It is a good thing to do for anyone trading US shares who are not US citizens or US resident (through international brokers) but it is not a requirement. Depends on if you want to pay more taxes or not.

Please do your own research, I am not a tax advisor.