Tax on Tax ?

Can any body explain this to me please. Just received my electricity bill from Iberdrola. Never took much notice of it before in detail and not long having purchased a property was happy with the amount. How ever, the other day on closer inspection I noticed that there is an electric tax on your consumption, fair enough you expect to pay some form of tax. But they add all this up to give a total and then charge IVA at 21% on top of this. So are they saying that tax is a luxury on which we pay IVA ? It's not a lot but times it by a few million customers it soon mounts up. Should it read amount for IVA exc electric tax then total amount inc electric tax ? It just seems strange even though we are in Spain. Is it right ?

As in the UK you are taxed on tax just look on the bright side the only things certain in life are tax and death if your paying tax no matter how much you are the lucky one!! come one you get sun with it in Spain

Thanks Scooby, I understand it now "it's sunshine tax"