The National Anti Fraud Network is a real public sector body that helps local authorities and other public organisations prevent fraud. Its website, nafn.gov.uk, sits on a government-owned domain that has been registered since the mid-1990s. That alone puts it in a different league from most sites you'd run a safety check on — the ownership is verified through the UK Cabinet Office, not hidden behind a privacy service.
That said, the site does have some technical roughness. It still supports very old encryption standards and doesn't set the browser security headers that prevent common web attacks. The page loads slowly and there are a few hidden HTML elements that could be remnants of plugins. None of these are dealbreakers for a government information and membership service, but they are worth noting if you're accustomed to modern security standards.
For anyone wondering "is nafn.gov.uk safe" — yes, it's a legitimate government site. If you're a public sector employee looking to report fraud or join the network, this is the correct place. The technical weaknesses are real but don't undermine the core trust signal: this is an official .gov.uk domain operated by a recognised public body.