I bought the Asus Flip C434 for $759 from Harvey Norman last Tuesday and just picked it up today. The deal came with a bonus $300 gift card.
At the time of order the GST was showing as $69 however on the invoice issued today in store the price shows $759 for the item and $0 for the gift card but GST shows as only $41.73. So looks like they calculated it on only the amount of $459. Minutes after leaving the store I was emailed a separate simple invoice from HN online which shows GST as $69.
Which invoice should I be using when I claim the TRS at the airport next month?
Any receipt that serves as a tax invoice (i.e. has the GST amount and ABN number on it). Use the TRS app to pre-fill data. They're not going to care about those miniscule amounts.
They waved me through when I claimed for 2 iPhones I was taking as a gift and didn't even ask me to take them out of backpack for proof. The guy said they have international travellers that claim tens of thousands of dollars worth of products so we're small fry.