If you have booked a cruise but not yet paid in full, you can assign the reservation to a travel agent within 30 days of the initial booking. However, some travel agencies have a reduced onboard credit amount for transferred reservations compared to new bookings.
You are correct that there is no fee for using a travel agent, since commissions are paid by
Disney Cruise.
Just to clarify what can and can’t be done on one’s own:
If you are using a travel agent, the travel agent must make any changes that involve the cruise booking. This includes making payments, cancelling or moving the reservation, adding or removing a passenger, and changing the room location or type.
I know changing the dining time, booking pre/post cruise transportation, and pre-paying gratuities can be done through a travel agent, but I am not sure whether they can also be booking by calling
DCL.
Even when using a travel agent, you can book excursions and ticketed onboard activities (including spa treatments, adult dining, ticketed character meets, and beverage tastings) on your own through the DCL website or app.
I have used a travel agent for cruise booking over the past 15 years with no issues. I simply email my agent with what I want — e.g. booking a new cruise or moving an existing reservation — and she calls DCL and emails me a confirmation when it’s all done.