Originally Posted by
MSPeconomist
One reason to register everyone is in case the other person gets locked out of the room (for example, forgets keycard or it stops working) when the primary guest isn't around. In such cases, the front desk absolutely will not and should not let the person enter the room (or the lounge, etc.).
This exact situation happened to me 2 weeks ago. I had 2 back to back reservations which FD agent combined when I checked in. The room keys were only keyed for the first reservation, so my wife had to go to front desk to get new keys, since I was away at work. If she had not been on the reservation, then she would be locked out and be pissed at me.
Another time in Paris, my daughter arrived at the hotel when I was away, but she was able to get a key because I had her name on the reservation.