I just added an extra person to my cabin and asked Carnival to "refare" me - stating that I knew it was a "soft sailing" since they still had lots of space available less than 2 weeks prior to the sailing. Well I was a verrrrry happy camper when my 3rd person went for $169 on a one week cruise. It turns out she reduced the original fares I had paid for two and added what a 3rd would cost. On this cruise I hadn't gone through a travel agent and I worked directly with Carnival. This last summer I booked through AAA and we got a refund from Carnival after they finally located my past passenger # - the refund was for the cost of the upgrade I should have had as a past passenger. It took a few months - but we got it.