FlyerTalk Evangelist and Ambassador: The British Airways Club
Join Date: Jun 2008
Location: Somewhere between 0 and 13,000 metres high
Programs: AF/KL Life Plat, BA GGL+GfL, ALL Diam, Hilton Diam, Marriott Gold, blablablah, etc
Posts: 33,195
Machines won't let you. Agents can do it (assuming you are within the right times) but it clearly takes skill and a lot of typing on their part so many will just say that they cannot. I have had NCE agents manage to do that for me multiple times.