Is there a simple answer to this question?

Is VAT applicable on a used 2012 Defender 90 2.2 XS, it has had windows / seats from new?

I am hearing many conflicting reports

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shouldn't be if it was originally registered as an estate car. If it was registered as a commercial, then VAT will apply, unless it has been already paid but not reclaimed.

According to Land Rovers price list, all new Defenders are plus VAT (they're all classed as commercials now irrespective of seats, windows etc including the XS). If you're buying it second hand from someone who isn't VAT registered then there shouldn't be any VAT as they have already took the hit, if you're buying from someone or a company that is VAT registered and they've reclaimed it then I think they're obliged to charge it when they sell it on.