It depends. Here's a nice example for you - A while ago the BBC ran a series on council house investigators and their cases. It was very clear for it, that councils don't routinely check whether a prospective council tenant (who'd eventually become a buyer) doesn't already own a property. No checks are done with HMRC for their income levels either.
Of course, if a future government just wants to round up dissidents and send them to camps, I'm sure it won't be that big of an issue. But as of right now, this is enough to stop routine fraud prevention, which is likely an immediate threat to far more people.