Stop falling for TVL's misinformation !
There still seems to be a widespread belief in the TV Licensing propaganda that you have to tell them if you don't need a licence, and that you have to let them in to your home in order to prove your innocence.
None of these myths is true. There is NO obligation whatsoever to communicate with TV Licensing or to let them in, except in the unlikely event that they have a valid search warrant.
Of course, the threat-o-grams will get ever more menacing, but if you don't need a licence you can happily ignore them or pop them into an unstamped envelope and send them back unopened.
But if the threats get tiresome, they can be stopped dead in their tracks (at least in England and Wales) simply by stating that they can't send the boys round because you have withdrawn their Implied Right of Access, and therefore that any further threats to do so will be dealt with under the Malicious Communications Act 1988.