It's a myth prisons are full of women who are there for non-payment of TV Licence.
For a start, it is not a criminal offence that carries a custodial sentence. What does potentially carry a custodial sentence is non-payment of the fine levied for watching without a licence.
The fine can be "up to" £1000, but more typically, in Scotland at least, it's usually in the region of £50-£75
Prosecutions for watching without a licence have plummeted over the past 15 years from around 200k-250k per year, to 44k most recently. In Scotland, it is a literal handful of cases per year, around 4-5, suggesting that Capita have simply given up trying to police the Licence north of the border.
The latest Gov FOI figures show that across the entirety of the UK there has not been a single TV Licence-related imprisonment in the UK since 2019, and IIRC before that, there were two cases since 2016, both of whom were males.
The reason this myth arose, is that it used to be the case that many women facing imprisonment on much more serious charges often had an outstanding prosecution for non-payment of fine, so as they were going to prison in any case, their lawyer/solicitor would ask the Sheriff/JP/Magistrate/Judge to take this into account, and as they were serving a custodial sentence in any case, let them serve a concurrent sentence to strike this from the books, as unlikely as it ever was to actually be prosecuted. This is why prisons were "full of women with convictions for non-payment of TV licence avoidance fine", even though that's not the actual reason why a single one of them was in prison.
Basically, nobody goes to jail for non-payment of TV licence, and the precipitous fall in numbers of fines for watching without a licence would suggest that even Capita aren't making the effort to catch people that they once were.