Our card is old and I'm doubtful that there is (currently) very much money on it. Do I understand that I can simply use a credit card????
Look at your credit card, if it has a "wi-fi" looking symbol on it, you are good to go. Visa, AmEx, and Mastercard are accepted. If your card is not contactless enabled, contact your card issuer, you may be able to get an updated one.
You simply tap your card on the sensor, just like the Oyster, tap out as well on the underground. Buses, you only tap in, not out. Use your card all day, overnight, the transaction will post as one charge. If you reach the cap for the day, that will be applied, if you are there long enough and use transport enough, a weekly cap will be applied. If your card charges a Foreign Transaction Fee, that will only be charged once per day, not each time you tap in or out.
Each of you need your own card or you can use a Phone or Watch with Apple/Google Pay, The cards, phones, and watches can be all tied to the same account, just each person needs a physical card or device.
This would be amazing!!
Yes, it really is, along with being able to tap to pay for most everything on your trip as you go. Heck, as your walking through the underground, you can even "tap" to tip the buskers.