I sell goods online and issue a tax invoice to my clients. But most of the goods are posted to the client directly from overseas, if the goods value is more than $1000, the buyers have to pay GST and duty to Australia custom. is this situation, should my invoice include GST or not? if yes, that means the buyer have to pay GST twice, if No, should I include it in GST free sales when I do my BAS return? Can anybody help to answer my question? Many thanks.