Yes, Carnival Cruise Line allows for the refund or adjustment of prepaid gratuities, but the process depends on when you make the request. If you have already paid your gratuities before the cruise begins and decide to cancel your booking within the allowed window, the prepaid amount is fully refunded to your original form of payment. If you are already on the ship and are dissatisfied with the service provided, you have the right to visit the Guest Service desk to adjust or remove the daily gratuity amount (Service Values) from your Sail & Sign account. However, this must be done before the end of the cruise; once you have disembarked and the final bill is processed, it is extremely difficult to obtain a refund. Carnival notes that these gratuities are distributed among the dining, bar, and cabin services staff, and they strongly encourage guests to keep them in place to support the crew. If you choose to remove them, the crew members who served you are notified of the adjustment. It is always recommended to discuss any service issues with management first to see if they can be resolved.