Currently the cost of a colour TV Licence is £145.50 a year while a black and white TV Licence costs £49.00. But technology has moved faster than the licensing laws and now you can legally watch TV (even BBC channels) without paying for a licence fee.
How can you legally avoid paying for a TV licence
Well the rules state that:
You need a TV Licence if you watch or record programmes “live” programmes. That means watching or recording at the same time (or virtually the same time) as they’re being broadcast, or distributed to the public in any other way.
As a general rule, if you’re watching a programme on a computer or other device at the same time as it’s being shown on TV, then the programme is “live” so you need a TV licence. If you use the live rewind function to restart a live programme or rewind a live stream for up to 2 hours, you also need a TV licence. This is because you’re still accessing the live simulcasts.
So with the advent of BBC iplayer, catchup TV players and products such as Netflix if you are not watching or recording live programmes you don't need a TV licence. And the reality is that a lot more people are doing exactly that - so could legally avoid paying for a TV licence altogether.
Further Reading
If you do watch or record live tv it still may be possible for you get a discounted tv licence. Read my post - 'Money tip #27 - Save money on your TV Licence'.