Can you point me to any examples? I ran a small business in the UK for several years and never heard of anything like it. The closest would be the Windfall Tax, but that targeted a small number of privatised utilities that were sold off on the cheap by a previous government. http://en.wikipedia.org/wiki/Windfall_Tax_%28United_Kingdom%...
Apologies, I got slightly confused with the "payments on account" scheme, which does not involve VAT in the UK. Elsewhere (I believe in Italy and France), the same approach is used for VAT as well.