For Phil (with apologies to Jake for posting on his thread):
Last bit first:
As far as HMRC and UKBA are concerned, it's YOUR responsibility to show that you've purchased an item (and paid the relevant taxes) here in the UK. (If you can't prove it, they can assume that you're trying to smuggle goods in). If you're travelling outside of the EU, the advice is to always carry your receipts to prove that you've not purchased things like watches while you where abroad.
If you buy something from a UK manufacturer, the Government will benefit through taxing that manufacturer's profits and from the VAT on your purchase. Unsurprisingly, the Chancellor isn't too happy about people buying from overseas unless the Exchequer can similarly benefit. So, just like all other countries, we have import taxes. (However, because the EU is a single tax zone, there's nothing to pay - other than on alcohol and tobacco products - when importing from within the EU, as long as you've paid local taxes on the goods. You only pay on imports from outside of the EU).
The first step in working out what you'll be charged for importing from a non-EU country is to apply the relevant tax rate. That varies depending upon the type of goods. See here:
http://www.google.co....1ZQtJeT1cwgfA&cad=rja
You'll see that watches attract 4.5% Import Tax, so your £500 watch would attract £22.50 in Import Tax.
The next step is to add VAT. That's charged on the price of the goods, on the cost of the carriage and on the Import Tax. (Yes, that really is a tax on a tax!). Let's suppose that you paid £20 carriage. If so, VAT would be charged upon £542.50. At the current 20% rate, that's £108.50. (A lower rate of VAT obviously applied when you imported your watch!).
Lastly (to add insult to injury!) there's a fee to be paid for assessing the taxes to be charged! That's currently £8 for items inspected by Parcelforce Worldwide (who carry out the task on behalf of HMRC).
So, at the current rates, you'd have to pay £22.50 + £108.50 + £8.00 = £139.00. It looks like you got off lightly!
Chris
PS: Some items can get you clobbered for far more tax. For example, although most clothing currently attracts 12% Import Tax, the USA is in breach of World Trade Organisation rules on subsidies to its cotton farmers. In consequence of that, the UK currently adds a further 15% 'ad valorum' tax, making the tax on cotton-based clothing from the USA come to 27%.