Most of my banking I bootstrapped from a physical interaction. The one provider I haven't had any physical interaction with I validated on the Financial Services Register: https://www.fca.org.uk/firms/financial-services-register
And if someone's managed to break gov.uk then I've got bigger problems.
I'll note, though, that most of the time I'm going to be using a credit card and it'll be obvious fairly quickly if whatever goods or services I've ordered don't appear. It's only really if I'm making multi-year investments (or going completely off the correct payment rails) that it's catastrophic if I make a mistake. See also: https://bam.kalzumeus.com/archive/no-payments-are-final/
The FCA website can be validated using the UK Government website: https://www.gov.uk/registration-with-the-financial-conduct-a...
And if someone's managed to break gov.uk then I've got bigger problems.
I'll note, though, that most of the time I'm going to be using a credit card and it'll be obvious fairly quickly if whatever goods or services I've ordered don't appear. It's only really if I'm making multi-year investments (or going completely off the correct payment rails) that it's catastrophic if I make a mistake. See also: https://bam.kalzumeus.com/archive/no-payments-are-final/