Only two situations where you can purchase double for one trip: (a) one mentioned above having part of the trip in one use year and the rest of the trip in the next use year; and (b) you own two different use years, e.g., Feb and June, and are booking part of the trip with one use year and the other part with the second use year, in which case you can get up to 24 OTUPs for each of those reservations..