If you book checked bags when you book an Easyjet flight, it's 12- 22/flight. This rises to 32/flight at check-in, then 45/flight at the gate-costs that easily make a budget flight not so purse-friendly. Checked-in bags are a maximum of 20kg so ensure you weigh before you go.tep 2. Call to claim your voucher. Have your booking reference and flight details to hand, then call Easyjet customer service on 0330 365 5000 (as it's an 03 number, the call will be part of your minutes allowance or cost no more than a standard number). You have to call-you can't claim by email or letter.