when I make an A to B trip, using Google Pay, what sometimes happens is that I can’t touch in/out as I haven’t caught mobile signal.
This might be a problem for two reasons
1) maximum fare (however, it looks like there’s some AI behind the scenes, which completes incomplete journeys on the principle of commuting between two places)
2) potential revenue inspection
The only 100% solution then seems to be using standard Contactless/Oyster.
Well, I suppose it does need signal since everytime this happened, I had no signal, which has already broken my journey lots of times, but I somehow always manage to stay within the three refunds per month, mostly thanks to AI.
Google Pay does not really do offline payment authorisations well on its own app (technically Google claims there is one offline chance for such payments at any one time on the phone but I never had it working, so I assume it has to be online only), this is why it is paramount to ensure the phone is online whilst paying.
I also can’t speak to Google Pay, but Apple Pay is capable of authorising a transaction on public transport only even when the phone has no signal and is out of power. With Apple this is a feature called “Express Travel” and needs to be turned on; I wonder if there is something similar on Android?