I see you haven't got an accountant mate. Mine has kept me under the VAT threshhold, worked out allowances for day travel and tax free incomes. My material costs, cleaning materials etc are all reckoned as lump sums to be deducted from income tax. Over the last 5 years, I reckon I've saved at least 7 thousand quid in tax and corporation taxes here.
If you ever go and speak to an accountant, I bet you'd be surprised at what you're paying too much of, or not saving that you could be. I'm just a cleaner, don't take my word for it, go and get an appointment. They're cost free. Well mine were anyway. I went to 4 different accountants.
Years ago, my wife used to do all my returns and tax. I ended up paying local corporation taxes of over 6K one year. By the time I'd taken my accountant on after my divorce. I realized that I should have got rebates, not bills!!!
I found asking people who know what they're talking about the best way to go about tax and book keeping. That's usually an accountant, not another windie.
Added later, My accountant costs me around 500 quid a year. That's cheap compared to what I'd pay without her help and advice.