[Twey]

We have official government ID (the national insurance number, roughly equivalent to a USian SSN), but names aren't expected to reliably link it in one hop, and we're politically averse to laws that require citizens to produce it in various circumstances, e.g. carrying ID cards, even though in practice most people do carry some form of government-sanctioned ID. Name changing is mostly limited by the fact that it becomes the duty of the person using a different name to laboriously link the new name to any previous names they've used wherever you need some paperwork in a different name. E.g. you need to provide your NI number to be employed, which typically means you need to have a paper trail back to it across any renames you might have had.