Saying Bitcoins is vouchers is wrong in my eyes. Only discount vouchers that are sold are Vat-able, all other vouchers are VAT free according to HMRC. So if Bitcoins are vouchers they are not Vat-able. I do believe that they are not vouchers and HMRC regardless of what they have said in the past will not treat them as vouchers.
This is simply wrong. Bitcoins *are* a VATable commodity and HMRC *will* expect you to pay VAT if you meet the threshold. Wishing on rainbows and unicorns that you'll be a 'special case' is willful ignorance.
See:
https://localbitcoins.com/forums/#!/regional/uk#uk-sellersbuyers-beware
Remember; Ignorance is no excuse in the eyes of the law.
Whilst that might be so written, reading on this and other forums there have been instances in the last week or 2 where HMRC have said treat Bitcoins as currency, and the guy who went to court argued that vouchers are not taxable, he won and did not have to pay any Vat. So I would suggest VAT is not applicable.