Matched Betting is a very interesting and established way to milk the bookies for tax-free money, and you can earn easily up to 1000 pound a month using it. But let's go through the basics first..
Matched betting is the use of bookmakers free bet promotions (As well as other types of promotions)
In simple terms, you sign up to a bookmaker that has (EG) "BET £5 GET £5 FREE" type bets. You then qualify for the promotion and bet on a game for however much you're required to. You then go to a betting exchange and bet for the opposite result (Make sure to sync the odds up)
The idea is, no matter which team wins, you get the majority if not all of your money back, AND a free bet to use.
There are literally hundreds of websites you can do this on and the profit is endless!
This is just a basic introduction to matched betting, but I've already earned over £500.
For more, just google "Matched Betting Guide" and you'll find out how people make thousands tax free!