Again, that is the exact opposite of what the various Carnival lines do. In 2020 on Princess (for a cruise that obviously never happened because of Covid), I tried to buy an excursion pre-cruise for both DW and myself. They would not split it, so even after using other OBC a few dollars ended up having to be charged. There are some who have reported when you call, they will then allow it to be split, but it was not worth the effort to try to call again to get a different representative for a relatively few dollars that would have been left in my OBC anyway and would get used on the ship.