The problem is that there's ultimately no due diligence you can do on a utility bill that can't be defeated by a fraudster. No utility will answer a call to con

The problem is that there's ultimately no due diligence you can do on a utility bill that can't be defeated by a fraudster. No utility will answer a call to confirm/deny someone's details (as it can be abused), and even then, utilities that don't rely on a physical location (wireless telecoms/internet) themselves can't prove (and don't particularly care about) the address they have on file so even a legitimate utility account doesn't guarantee the account holder actually has access to that address. The banks are only requiring them to cover their ass because the country seems to have accepted the idea that a utility bill is somehow an authoritative document, so they can claim their due diligence was up to scratch (well they're not wrong, as you can't reasonably do any better) if things go wrong.