as much as I would like to keep it, I think I would return it, £150,000 is a lot of money, people will notice that you are living a more luxurious life than you were before, if you put it in the bank people will ask questions, if you keep it as cash then you are taking risks by walking round with large amounts to pay for stuff plus it looks suspicious. Then there is the CCTV, not knowing if the police are on to you, I think I would get pretty paranoid.