[MovedGoalPosts]

A business just needs a proper receipt, it doesn't have to be VAT after all you can trade quite legally and not be VAT registered provided you don't have a big turnover. that is how most small one man band traders will start up. All that happens is that a VAT registered business can't reclaim / offset the VAT if the invoice is all inclusive and thus would compare an all inclusive cost to a VAT plus cost.

As for a simple office no bells and whistles PC I buy our office stuff direct from Dell

I'd discount linux. For most users you need true MS Office software, not just a compatible, to be sure you can share your documents with other businesses and clients. If you know what you are doing then star office and linux might be an option, but only if you want the hassle, and in business environments you just don't need that. Hence business being primarily wedded to Windows.