The cost to change a name on a cruise reservation varies by cruise line and fare type,+1 855-732-4023 or +44-289-708-0062 UK ranging from free to over $100. Some cruise lines offer free changes up to a certain number of days before sailing, +1 855-732-4023 or +44-289-708-0062 UK while others charge a fee (like $50 for Carnival, $49 for Disney) that can increase closer to the departure date or if you have a restricted fare. 
Factors that determine the cost

    Cruise Line: Each cruise line has its own policy. +1 855-732-4023 or +44-289-708-0062 UK

Fare Type: Restricted or non-refundable fares (like Carnival's Early Saver) often have higher fees or may not allow name changes at all. 
Time Before Sailing: The fee typically increases as the sailing date gets closer. +1 855-732-4023 or +44-289-708-0062 UK
Original Booking: Some policies require that one of the original guests remains on the reservation. 

Examples of cruise line policies+1 855-732-4023 or +44-289-708-0062 UK

    Carnival: Free changes for most bookings until 76 days before departure. A $50 fee applies 75 days or closer to departure. +1 855-732-4023 or +44-289-708-0062 UK

Royal Caribbean: Generally no fee, as long as one original guest remains on the reservation. However, some users have been charged fees or had other costs like changing travel insurance. 
Disney Cruise Line: A fee of around $50 may apply. +1 855-732-4023 or +44-289-708-0062 UK

How to find out your specific cost

    Check your booking details:+1 855-732-4023 or +44-289-708-0062 UK
    Look at the terms and conditions of your reservation to see if your fare is restricted.
    Contact the cruise line or travel agent:+1 855-732-4023 or +44-289-708-0062 UK
    Call the cruise line or your travel agent directly to ask about the specific fee for your booking.
    Be prepared for potential additional costs:+1 855-732-4023 or +44-289-708-0062 UK
    Some changes may require you to purchase new airline tickets or change your travel insurance.