Please clarify "contactless card" for the tube

same price whether Oyster or debit/credit card (foreign transaction fees may apply - check with your issuer)

https://tfl.gov.uk/fares/how-to-pay-and-where-to-buy-tickets-and-oyster/pay-as-you-go/contactless-and-mobile-pay-as-you-go

Actually some combinations of journeys are cheaper using a Contactless Card than Oyster due to the way the daily cap is applied
Needs to have the contactless symbol it. Understand not all US cards have it

I understand that to benefit from the cap you should use the same card via the same mechanism, meaning phone, watch or actual card.

Maybe back the bus up a bit to clarify something. The chip in itself does not make a CC contactless. The card must be enabled with Near Field Capability, the universal symbol for this looks like a wi-fi symbol, curved lines getting smaller to bigger. If you have that, and a card accepted by TFL, then you should be good. I would though verify that you do not pay fees for international transactions.

Then, yeah, you use it just like an Oyster card, tap it when entering, and when leaving. The system will track your charges, and cap it for the day, just like an oyster card.

Couple of other details, only one person per card, you can't share, if you want the cost to cap in a day/week then you need to use the same card each time/day. You can also use NFC capable devices (Phones, Apple Watches, etc.) with Apple or Google pay,

To expand on what Roger Brown said up thread that contactless fares can sometimes be cheaper than an Oystercard see the below short video, made 5 years ago by enthusiasts, perhaps a bit nuanced or nerdy for short stay visitors but still interesting, you will notice that it’s an American Express contactless card.

https://m.youtube.com/watch?v=1w95ULafeSY

Mrs Carol, we (US) commonly call this feature "tap". If you haven't used tap to pay, try it at home several times before you go so you know your card works, and see how it works. Some people struggle with the concept.

When you say only one person per card, what about two people who have separate cards but on one account?

Usually the two cards will each have a different number even though they both are on the same account. That is the way it is with our Capital One cards and with Delta branded cards on Amex. So your tube trips will be treated separately.

Our Chase Sapphire Reserve Card has the same account number on both of our cards, but each card has our own name on it. I'm still confused!

It's so easy to simply buy a card and use it, that's what I plan on doing. Last time, my Apply Pay suddenly stopped working. Also, I like having a physical Oyster Card. It seems fun (don't know why).

Piggybacking on your post...hope you don't mind...

Does one have to register their credit card, or just start using it? I can't find that as a Q&A on the TfL site.

Someone here or on another post mentioned the FOLC (fear of loosing card) when tapping with a credit card. I have FOLC as well and may just go ahead and buy the Oyster card.

I still have 2 unregistered Oyster cards. They worked as of Jan 2020 when I was last there. I think registered cards allow you to report as lost or stolen and possibly to transfer the balance to a new one. May allow for online addition of funds too.

@Becky: No need to register your credit/debit card, but you must keep using the same card for fares and capping to work, you can create an oyster online account and link your bank credit cards to this.

If you are FOLC wary about losing or handling your bank credit cards use a regular Oystercard not the visitor version, you can register and create an online account, check full journey, submit incomplete journey fare reclaims if you didn’t tap correctly, if you lose your card you can temporarily block the account, your credit monies are then safeguarded. If necessary Use your accommodation address when registering.

Oyster cards are good to use as soon as you load money onto them. No need to register. (You need a UK address to do so.)

My current card is about 6 years old and still works fine. The money loaded never expires.

I registered mine because I make frequent trips to London. It allows me to log on and see how much I still have on my card.

Thanks Dennis.Loline for that information. I decided to compromise...I added a debit card to my Apple Pay and will tap with my phone. My phone has a wrist strap and is too big to slip out of my hand or pocket like a card.

Thanks for your help. I am now ready to tap!

Would a contactless Discover card work for the tube, or does it have to be a visa or mastercard? I know that discover wasn't widely accepted the last time we were there...

Would a contactless Discover card work for the tube

No. Only American Express, Mastercard/Maestro, and Visa/V-Pay are accepted, though they include the warning that some cards issued outside the UK "may" not work.

https://tfl.gov.uk/fares/how-to-pay-and-where-to-buy-tickets-and-oyster/pay-as-you-go/contactless-and-mobile-pay-as-you-go

Keep in mind that a Senior Railcard can be linked to your Oyster Card and will give you a 1/3 fare discount so long as you travel off peak. Peak is usually 6:30 am to 9:30 am, but the time can vary per route. It is not possible to link a railcard to a contactless payment card. If you are in London for a full week you can also get a weekly cap by adding a Travelcard for the days you are actually there, Wednesday to Tuesday, for example. Otherwise, the weekly cap runs Monday to Sunday. Anyone can get a Senior Railcard. No need to be a UK resident. The 3 year deal is particularly good if you plan to return frequently over a 3 year period. It doesn't take many train trips to pay you back. I have to say, though, my favorite transport within London is the buses and my feet. You see so much more that way.

you'll be lucky to find any English business which accepts Discover.

My husband and I both have the same VISA number but two different cards: one with my name on it and the other with his name. Are those considered the same card?

Discover in the UK is only accepted at places that take Diners Club. This isn't zero but for practical purposes might as well be.

Lindy, if both cards have the same number I would expect them to be treated as one card by the Tube. I think only one of you could safely use the card.

This RS forum seems not to show 'total views' per thread, but I'll bet that this useful question by Mrs. Carol has been read as often as any here. Lots of pertinent advice above. Thanks to all, including OP.
I am done. the Brit-bound