I've been getting stroppy with a company for whom I recently did some work. I sent them bank details for payment obviously, but that is not enough. They won't pay. They want some letter from my bank. To prove I exist? They saw me in person. To prove I'm respectable? I'm probably more respectable than they are. They are French so their whole purpose in life is to do paperwork instead of working. In other cases, when the payment happens before the work then I always call a company's bluff, "I don't think you need that paperwork so I'm not sending it. If you don't pay on time anyway then I'm not doing the work." It's never failed so far, proving that this paperwork is just an exercise to find employment for otherwise pointless people.I'd rather ask a psychologist to figure out the British aversion to ID cards.