You can easily STOP the nastygrams !
@ Will Godfrey
I didn't have a TV and just ignored the fortnightly nastygrams, letting them build up into a pile about two feet high. They became ever nastier, with pictures of courtrooms etc, and were sometimes disguised to look like bank PIN notifications or payslips.
On principle, I still kept ignoring them.
It might have been different if they had politely asked me to confirm that I didn't need a licence, explaining that there was no obligation whatsoever to respond, but they'd be eternally grateful if I would just return the enclosed post-paid declaration form: I might well have done so.
Eventually the goons started to send their nastygrams by Registered mail. As I was always at work when the postman called, that necessitated an unnecessary trip to the Head Post Office the following Saturday. It would have been tempting to keep ignoring them, but there was always the risk that one of them might be something I wanted (e.g. a bank card) or something I didn't want but needed to know about (e.g. a speed camera ticket).
Enough was enough, so many years ago I sent a letter withdrawing their Implied Right of Access (signed as The Occupier). For good measure I also stated that I was fully aware of the penalties for watching live TV without a licence so there was no justification for reminding me every fortnight and, as they could no longer send the boys round, continuing to send scary letters threatening to do so would be an offence under the Malicious Communications Act 1988.
Result: they confirmed they would never bother me again - and they haven't !