when do i have to list 2nd traveler?

[layteacher]

I have booked a cruise for next Spring 2020. I have a friend going with me. When is the latest time I can add here name to the room? Just in case she cant go.. 

[bury me at sea]

Please check with Carnival.  I believe anytime prior to final payment date, as long as you are adding only one person to a cabin meant for two people.

[maryred]

Yes do call your PVP, travel professional, or the CS # on your booking confirmation. Each booking rate has it own terms and conditions some of which affect your ability to add a passenger or even list an unconfirmed person as TBA. Some bookings will allow you to book as solo then "upgrade" to the cabin's passenger capacity at anytime (up to 2 days before sailing) with no fees or penalties as long as your muster station has not maxed out. While others requires all name to be on the booking by a certain time after making the booking up to just before the final payment date or any changes to the booking are construed as a cancelation and rebook situation. Then there are others you can add names but it will incur an administrative change fee.

[cellfree]

My PVP only puts my name on when I book a Cabin for two both my husband (or anyone else) amd myself so that should we need to cancel we only lose $50 rather than $100. I always have up until final payment (although I do add his name sooner) to add his name. 

[Stallion]

I've added someone as late as 5 days before cruise but NOTE if its during spring break and there are a bunch of 3rd and 4th passengers the ship could hit the 'lifeboat limit' and then you might have a problem that late