When do I need to complete the Post-Booking Bonus form to qualify for my onboard credit? February 18, 2019 15:20 Updated To qualify for your onboard credit, you must fill out the redemption form no later than 21 days prior to departure. Related articles What is my Post-Booking On Board Credit amount? How do I choose between Onboard Credit or Amazon.com gift card? How can I get a copy of my reservation details (invoice)? How do I access my Cruises Only reservation? Should I purchase a beverage package from the cruise line?