Contactless payment/Apple Pay

That's a good question. If I understand it correctly, the system deducts a "full fare" amount from the account, then refunds the difference when the journey is completed. As the journey details cannot be stored on a contactless bank card, the back-haul must pick up the slack and determine where your journey began.
As ApplePay would, I expect, have a different "card" number from the plastic, even though it's the same bank account, so that the bank can differentiate which payment method was used for a transaction, then I expect it would not be able to tie the two taps together and work out where you entered the system.
If it attempted to use the bank account number rather than a number uniquely identifying the plastic, then the system wouldn't be able to process travel for, e.g., a husband and wife with a joint bank account - they both board at Liverpool Street, say, and one exits at Bank, the other at Oxford Street. Who made what journey?

Does Apple Pay really not work if the device is switched off?

I would assume that Apple Pay (and its rivals, some of which are yet to be launched here in the UK) do not transmit the credit card data with every transaction, so there should be a greater element of safety against fraudsters reading data packets and using wi-fi to interrogate RFID chips and harvest sensitive banking data.

But from the point of view of minimal chance of hassle (as described by the OP) then yes, your suggestion is optimal. I do something very similar, albeit with the one Oystercard. 

Simon

If you use ApplePay on your device to touch in you must use the same device to tap out, and for the rest of your daily travel to take advantage of capping. Even if you have the same card, say, on an iPhone, Apple Watch and plastic form, you cannot swap between the devices as each will have a different identifier; the plastic card will be the long number, for ApplePay it is a generated character string that links the payments together.

Unlike an Oyster card no payment is taken when you first (or subsequently) tap in. Each tap is recorded and all are downloaded at the end of the traffic day and linked together; at this point your card will be charged the cheapest rate for the journeys you have made, using any combination of zonal caps and extension fares as appropriate.

When using ApplePay the device (quite obviously) has to be switched on, as it is 'active' rather than 'passive'. The user selects which card they wish to use from the 'Wallet' app and then authenticates via TouchID to transmit the details. As ApplePay can store several payment cards, store cards and loyalty cards (etc) it would be impossible to have the system operate whilst the device is switched off.

Any incomplete journeys or maximum charges on ApplePay (or any other contactless method of payment) can be resolved on the TfL website or over the phone to the Oyster helpline, although experience suggests they won't give you full refunds if you haven't used the system correctly (quite rightly, in my opinion).

Then that's down to the user not ensuring that their device has enough charge to last the journey. Most people seem to be aware of this, and I have had only one person use the "battery flat" excuse since ApplePay was rolled out.

If you can't take control and ensure that you have a valid payment method (a dead phone is not valid) then you deserve a penalty fare.

I must to not understanding how ApplePay works; I hadn't realised the variety of cards that could be registered, which then necessitates being able to switch between which card is simulated. The omission seems to be the inability for the device to retain memory of whichever card it's pretending to be when the battery dies. If the device is simply a reference number, then why can't it still be interrogated to yield that number when turned off? Oyster/Contactless manage it!

TfL have at least put all of this information online:

Apple Pay


The 'convenience' over Oyster is that there's no topping up, which is helpful. That said, the first few times I tried Apple Pay on TfL it didn't work at all.
Personally, I find contactless and Apple Pay to be about the same amount of time to touch in/out, but that Oyster is noticeably faster.

It's too fiddly to use, imagine in the morning rush hour trying to open your app and touch it onto the gate correctly amongst a rush hour crowd - not too convenient.
You also need both hands free, which means added inconvenience - it's just a gimmick for these Iphone fans to play with!

How does Apple Pay work in the event of an on-train ticket inspection? Oyster cards carry (so I understand) a trace of having been touched in, but the Apple Pay doesn't.

Thanks - I hadn't realised it would be legal for an unpaid fare challenge to be made other than in person and at the time of the offence by the inspector. Presumably they can only try to fine you, not prosecute you for non-payment, as the credit card company would presumably not release your contact details (no pun intended)? Not planning on putting this to the test, by the way, just interested!

I have had my iPhone checked whilst on a Thameslink train heading towards Sutton I was told to press the home button twice as usual to activate the app it recognises if the card has been tapped in or not it won't say an amount as it totals up at end of day (to enable capping etc)