To bid for an upgrade on Lufthansa, visit their website and select my booking option from the homepage. Then enter the booking reference number and last name for identification. After that, enter all the required details, then check if your flight is eligible for a Lufthansa bid for upgrade or not. After checking, choose your desired upgrade class, place your bid within the suggested range, and enter payment details. You’ll receive an email confirmation, and if accepted, your upgrade will be confirmed 24 to 72 hours before departure. However, bidding is subject to availability and eligibility.