Join Date: Feb 2006
Location: Cockeysville, MD
Programs: Marriott Rewards Lifetime Titanium, Amex Plat, Hertz Gold 5*, National Exec, AA Plat
Posts: 9,501
Is it a travel package (5 or 7 night cert)? If so, I would only cancel or change via phone. Too many times, they have vanished for me. I always get them back, but that is a pain.
All other certs go back seamlessly and instantly. Then you can reserve again.