Lots to go into (was sole trader, then Ltd company, now employed – yuck)
IR35 killed it for me, thing is I was not a employee in disguise but actually invested a lot of my profit into R&D and equipment and took on research contracts with MoD and funding bodies but everyone got scared of the risk and just declared contracts inside IR35. On £500 a day that was £900 a week in tax.
Currently employed but hate it and trying to get out.
Anyway, what I came here to say is if you dont “need” the money then either put it in the company accounts for when you do but you will need to pay corporation tax OR put it in your pension. I still have reserves from when I was consulting so put 30% of my salary into my pension. I try and balance it so I take home just what I need. If I want to buy anything out of the ordinary I dip into my reserves.