'Value added tax' was invented by the same (oxy)moron that came up with 'Microsoft Works'
It's just
another tax & one that was introduced (presumably) because some politician wanted to increase tax but say 'income tax has not increased under our administration'. Stealth Tax, taxation by the back door (and it wouldn't surprise me if the politicians tax
that before long, too

)
VAT supposedly applies to non essential items.
For example, childrens' clothes are deemed essential, but adults' clothes are not. Presumably, post-pubescent hair is supposed to keep us adults warm enough and not walking around naked is sheer extravagance!
There was an interesting debate a while back on the reason why VAT was being applied to female sanitary products (another luxury, in the eyes of the politicians).
VAT does not apply to most food... however, there are some interesting anomalies: raw tiger king prawns, fillet steak (not sure what the US cut is called - it's the most expensive & tender cut of beef) and coffee are non-VAT items. VAT is applied to 'processed' foods and alcohol. Buy some bread, salad and chicken, take them home & make a sandwich - you will not pay VAT, but if a company does this for you & places said sandwich in a plastic package, you pay VAT for the priviledge. Coffee is roasted, ground & packaged, but this is not deemed a processed food, whereas the act of pouring spring water into a bottle is "processing".
Heating and lighting your house is a luxury until you draw a pension, then it becomes a necessity. Fuel oil, coal, gas and electricity are taxed @ 5%, but pensioners receive a £200 'winter heating' allowance in their State pension.
Confused
Remember: Politics - Poli = many & Tics = blood-sucking creatures.