How do I redeem the Onboard Credit? March 21, 2019 14:45 Updated To redeem your Onboard Credit , you must fill out the redemption form after booking a qualifying cruise. This form must be completed no later than 21 days prior to departure. You can also access your invoice at: My Cruise Reservation. Related articles When do I need to complete the Post-Booking Bonus form to qualify for my onboard credit? When will my onboard credit be applied to my account? What is my Post-Booking onboard spending amount? How do I pre-register with the cruise line? When will I get my cash back rebate?