From what I've grasped from the gov.uk website, you can gift as much as you like to anyone without paying any tax, as long as you don't die in the next 7 years. So why doesn't everyone just gift money to each other, to avoid paying tax?
For example, I could let 3 lodgers live with me for free (a room each). They could gift me £4000 a year each. I would pay no tax and keep £12,000 a year. If instead they paid me rent, I would pay income tax on anything over £7,500 (thanks to the Rent-a-room scheme).
I'm guessing this is too good to be true, but if so, how would the law argue against this?