When booking your flight ticket, most airlines offer the option to purchase extra baggage online. If it is not possible to add extra baggage simultaneously, we recommend purchasing the extra special services to save on our service fees when adding baggage afterwards. Unfortunately this option is not available with so-called ‘Codeshare flights’ (flights operated by partner airlines of the airline which you received the ticket) and combinations of airlines. In most cases it is also possible to add baggage after you have made your flight booking by logging into My Trips. For some airlines such as United Airlines, you can only purchase baggage at the airport.