TV license peculiarities
A couple of interesting points perhaps....
1) Some types of UPS (the expensive ones) emit mains type power but it's not mains power. This is because the batteries are charged from the mains, and the output power from the unit is created from the batteries via an inverter. These devices are popular in situations where mains power is of a poor quality (poor phase, varying voltate etc)
2) From what I remember though it's not about batteries or mains it is about an internal power supply. The law hasn't changed, but the TVL do change the interpretation of it from time to time. Therefore the UPS in point 1 does need a license under the old definition but under a new definition of mains powered, it could be argued that it does not need a license.
3) For people selling tv equipment, you can license the business for free. TV shops, computer shops, tv repair shops, etc - they all need registering for a tv license but it's free. You will be given excel spreadsheets and booklets and you must record each and every sale and pass the details on to TVL
4) Under the old definition, you needed a license for devices capable of receiving a signal. This used to mean removing tuners etc. This is not pushed as much now though. The reason perhaps for this is that many mobile phone users, laptop users and computer users now have a device which is capable of receiving live tv signals.
5) The actual law though talks about radio signals and doesn't really mention the internet in the slightest. Therefore, watching even live tv over the internet may not require a license. However if you are using wi-fi to watch live tv, then broadcasting and receiving is taking place so it could be argued that you need a license.
There are a LOT of grey areas but the law is usually reasonable. TVL though may not be. If in doubt talk to them and get it in writing - I've tried on a number of occasions but they don't like to put stuff in writing.
However, the BBC website states quite clearly that you do not need a license to watch the stuff on iplayer. Therefore, stay away from live stuff and you don't need to worry.
You can watch live telly at the local pub. You can buy a lot of pints for the price of a sky subscription and tv license.