Tax invoices for taxable sales that total less than $1,000 must include enough information to enable the following to be clearly ascertained:
that the document is intended as a tax invoice
the seller's identity
the seller's Australian business number (ABN)
the date the tax invoice was issued
a brief description of the items sold, including the quantity (if applicable) and the price of what is sold
the GST amount (if any) payable in relation to the sale - this can be shown separately or, if the GST to be paid is exactly one-eleventh of the total price, as a statement such as 'Total price includes GST'
the extent that each sale to which the document relates is a taxable sale.