Seems that many sellers don't understand the Ebay rules in respect of auction style listings. As a seller using the standard Auction style listing you may not request that the buyer pays VAT @15% on top of his or her winning bid regardless to your Vat status and as a consequence of this, if you do ask a customer to pay such a tax the buyer may refuse to complete the sale and leave you negative feedback .However, you may charge VAT on top of a classified listing ... heres an extract on the ebay rules for your attention :
As eBay is primarily a consumer marketplace, from February 20th 2008, users will no longer be permitted to add VAT to the final item price after the item has been won.
If VAT is legally due, the seller bears the responsibility of paying that VAT to the appropriate authorities according to any applicable laws and regulations. If there is any question as to the seller's VAT responsibilities, the seller should consult an independent tax advisor and/or local tax authority.