Lets say if you want to try setting up all items with a 17.5% discount (equivalent to UK VAT) and then add it back with the VAT setting.
By using forms for all products:
<form action="https://storename.foxycart.com/cart" class="foxycart" method="post"> <input type="hidden" name="name" value="PRODUCT (15ml)" /> <input type="hidden" name="price" value="45.00" /> <input type="submit" class="submitbf" value="" /> <input type="hidden" name="discount_price_percentage" value="VAT Tax{0-17.5}" /> </form>
More info on discounts here: http://wiki.foxycart.com/getting_started/adding_links_and_forms#discounts