As little as possible, but then it still seems too much.
We pay thousands and thousands in tax, when you take VAT, fuel duty, council tax and probably lots of other taxes I don't even realise. I'm sure there's VAT on condoms, so the tax man even taxes your 'personal life'.
However, I was stung this year and had to pay 'on account', where I had to pay 04/05 tax bill AND 06/07 tax bill based on my 04/05 accounts.
That really stung me, and I don't think is right, since I've paid tax on money I may not have yet earnt, if you see what I mean.
Imagine this years profit was exactly the same as last years, then I've paid all my tax uptil April next year; yet I've not earnt that money yet.
I think it's wrong, whinge, whinge, whinge, etc.