I don't know nowadays, but in 2003 you did not need an ID to fly within the Schengen area. I went with a group to an event in Greece and somebody had forgotten

I don't know nowadays, but in 2003 you did not need an ID to fly within the Schengen area. I went with a group to an event in Greece and somebody had forgotten hid ID at home and only noticed at the airport. No problem the german airline agent checked him in, and he went through security screening without an id. (Boarding pass was enough) But when he wanted to fly back, the airline agent on the greek side insisted that he needed an ID to check in. So he had to prolong his stay, to get documents from the embassy and book another flight a few days later.