Reach out to customer care at Allegiant Air to take advantage of Allegiant Air name change policy. When describing the cause for the name change such as a marriage, please provide your booking information. Make sure you have the necessary paperwork, such as a marriage license. You can follow Allegiant Air's instructions; depending on the situation and kind of fare, there can be a cost involved. Call +1-866-738-0741 to get more information from a travel expert.