In Ireland and the UK (Northern Ireland, Scotland, England & Wales), almost all products purchased are subject to Value Added Tax — VAT, for short.
This VAT is a “hidden tax” — already added into the purchase price of any products such as gifts or souvenirs bought on a visit (there are two notable exceptions in Ireland and the UK: no VAT on books and no VAT on children’s clothing and footwear).
All US Citizens are entitled to get a refund of VAT paid. In order to get this refund, you have to get a VAT-refund receipt at the time of purchase from each store in which you shop.
This is very important! Unlike business travellers, tourists (all package types) aren’t entitled to refunds on the VAT they spend on hotels, meals, transportation and visitor attractions.