When I was a nipper my parents used to be Magistrates Courts Clerks, and they got a lot of trade from TV licensing.
Their usual MO was to knock on a door in the married quarters of the local army base, which would be answered by the wife of the soldier serving abroad. 'Where's your license,' bullyboy would say, and the wife would answer 'oh, I'm sure he's put it here somewhere, why don't you come in.'
Having been invited through the door, like a vampire, bullyboy would be able to see the TV on. When it turned out the soldier had either forgotten to renew the license or was unable to renew it, what with being abroad somewhere being shot at, the wife would be charged, given a criminal conviction, and fined £400.
This caused some interesting discussions at the dinner table.