Very difficult to quantify. Expenses can vary wildly. Some years just the unit rental and water bill and a few misc. items. Other years big van repairs, equipment replacements etc. Some people have facilities at home that mean they don't need a unit so even less outlay for them. Some have to pay wages to others.
I suppose your 40% might be thereabouts on average for a sole trader but there are so many things that can happen.
David if your paying out 40% in expenses to clean windows then something is wrong, the problem is that a lot of
guys work their expenses out on a yearly basis.
They confuse expenses with the cash flow needed to run your business for that year.
Will give you an example... lets say you need a new R.O. membrane this year, that will cost your business £250 which
you will need to keep your business running.
But this is not a yearly expense as you could get 5 years off use from it.
Indeed. I plucked 40% out of the air without consulting my records.. I have hit that (and more) as a maximum though - but not an average.
Mind you, rent and water can exceed £2k. Fuel can be another £2k. In one exceptionally bad year, there was nearly £3k for van repairs. Add in another £3k for poles, brushes, new 4040 membrane, resin, accountancy fee, misc connectors, printer/toner, telephone.
I think I probably exceeded 40% in my first year of WFPing when you consider that I bought a van and system too. Also, turnover wasn't so great because part of that first year I was adapting from trad so much slower initially.
But, as you rightly say, many of those items are spread over multiple years.