Oh good question. Firstly VAT is an EU creation so I don't think you could incorp that properly into a domestic system. I suppose the best idea would be a super means tested tax. The beaurocracy of it would be a nightmare, but I've always thought it would be a fairer tax than one on consumption like Excise duties or VAT. COuncil tax is another that would benefit from the means testing system. However I expect that it would be quite unpalatable for the UK population to pay their tax into one system as they'd probably be horrified by how much they do pay in various "stealth" taxes. Not that I think this is a bad thing, but I'll start ranting about public services if I'm not careful... So in conclusion we SHOULD have an all incompassing means0tested tax, but the effect would be total rejection by the public unfortunately