Here in the UK (where tipping is a different beast entirely to the US) every taxi I've ever taken has been paid for in cash. I think this is still the norm beca

Here in the UK (where tipping is a different beast entirely to the US) every taxi I've ever taken has been paid for in cash. I think this is still the norm because every fixed-fare I've had has been priced a few ££ below a round-figure in expectation of "keep the change". That said, if I was paying by card via an app (and I've never used Uber) I would absolutely expect not to tip or have to talk money with the driver at all. It just seems rather unprofessional.