Share your insights or perspective on the financial matter presented in the input.

Work on the side for my wife's company
In the US, you'd run the risk of being accused of fraud if this weren't set up properly.  It would only be proper if your wife could show that she were involved, acting as your agent, bookkeeper, etc. Even so, to suggest that your time is billed at one rate but you are only paid a tiny fraction of that is still a high risk alert.  I believe the expression "if it quacks like a duck..." is pretty universal. If not, I'll edit in a clarification.  note -I know OP is in UK, but I imagine tax collection is pretty similar in this regard.