When is the proper time to ask for an upgrade on an airplane?

Question

I've never been upgraded, well except when I was 7, but then they said I couldn't go by myself. I'm not saying that I will get upgraded, but am I supposed to ask? and when? how?

Answer 1

Go up to whoever is at the desk where you board the plane and ask there. Thats what I did last May. You just ask if there is any way you could be upgraded. When I asked, we could of been but it would of cost $150 extra each. I said no thanks. That was Delta airlines. Each airline might be different.

Answer 2

You can request them when the flight has taken off.

Answer 3

When you show them cash