Do my wife and I need separate cards when we travel on the Tube at the same time or can I swipe it once for her and once for me after she hands it to me?
Dick,
Aside from the small deposit paid for the Oyster Card at the time of purchase, you wouldn't really save anything as two fares would be deducted from your balance each time you swipe the card.
More importantly, I suspect that each card has a unique I.D. so the system may not allow swiping it twice through the same reader at the same time.
The Oyster card is personal. You swipe in and swipe out at the other end. If you arrive at a station without an automatic barrier, such as a remote one, you MUST find the little round swipe pad and swipe out. If you don't, a very high charge will be applied for the route.
You need one, and your wife needs one. You can't swipe in twice before it is swiped out.
Thanks! I'll get two. That was an easy one.