You can call the call center and ask for 15kg luggage. (ps plus baggage fee won't be particularly expensive. According to the online charge, 15kg is 25aud). If you make a phone call? 0? 2 Center customer service replied that you can't handle it. When you check in directly at the airport, you can only add the baggage fee. You can tell him that there is a confirmation form on Tiger Airways website that you can buy luggage by phone, and the cost will be cheaper than going to the airport. The method is to report the credit card number and the three letters on the back. Then another confirmation will be sent to the mailbox. Please go directly to the counter when you arrive at the airport. Be careful here, they may not understand that you bought your luggage by phone. Just tell them that you bought your luggage by phone (at this time, the confirmation sheet should also have the logo of 15kg luggage), and the counter will help you confirm it and then give you your boarding pass.