I was able to modify online one of the bounce backs we have the other week to change the resort and dates, but it's been hit or miss with the rest of them. Some I can no problem, others it says I have to call, others appear like I can do it online, but when I get to the point of switching I get an error saying I have to call. There doesn't seem to be a rhyme or reason as to which ones actually can be modified online for us.