Can I add a 3rd and 4th guest to a casino certificate later?

[Jrw118]

I just received a cruise certificate from my land-based casino. It is for a free interior cabin. Can I book the first two passengers now and add the third and fourth at a later date? The final payment date will not be until November 30, 2015

[lbendick]

We will be leaving this weekend for our third cruise using a land based free casino certificate. For all of them unless you upgraded to OV or balcony full payment had to be made upon booking for just two people. Any time you make any changes upgrades adding of people, then you are only required to make the $250/pp for a 7 day deposit. Yes I have added the kids a later date upon one condition. It is not a capacity controlled sailing date meaning if you book a cabin with an occupancy of four it cant be initially booked with only 2 passengers.

[Jrw118]

I am upgrading to a 6m on the Dream. When I called carnival they told me I would have to pay in full for all passengers at booking even though final payment date is November 30???? So I am trying to book just first 2 ($95 upgrade fee and taxes/port charges)