Apparently some emails are circulating the web with fake codes for a Halo 4 Beta. The folks at 343 Industries quickly cleared up the matter via twitter. Content editor David Ellis posted this recently on twitter.
If you see a page claiming to allow you to sign up for a Halo 4 beta be advised, IT’S A FAKE.
There has been no official word if there will even be a beta for Halo 4, but you will be the first to know when we receive official word.