(Pocket-lint) - As soon as Apple releases anything, many in the UK quickly scour the US Apple store site to compare prices. And often, thanks to exchange rates and duties, the kit over there turns out to be less expensive, even after state tax.

If you are heading to America on holiday or business, it's tempting therefore to hold off from buying a new iPhone, iPad or MacBook until you are Stateside.

However, there's one device that definitely shouldn't be on your shopping list: the cellular Apple Watch Series 3. The US version of the LTE smartwatch doesn't represent a bargain for Brits because it doesn't actually work in the UK. It doesn't actually work outside of the US, in fact.

The watch part does, of course, when connected to an iPhone, but the LTE bands used in the cellular Apple Watch 3 are US specific. You will need a UK version - currently exclusive to EE - to use mobile broadband connectivity in the UK.

Both EE and Apple told us that was the case, and it reminds us of the iPhone 5 or 3G versions of iPad when they first came out. Maybe one day the tech used will be more global, but not now.

It's a shame, because the LTE Apple Watch Series 3 starts at the equivalent of £295 in the States (before state tax), whereas it is £399 in the UK.

You'll just have to bite the bullet and pay the full whack, plus the £5 a month extra on your EE plan. Either that, or you can always opt for a US version of the non-cellular Apple Watch 3. That's the equivalent of £243 before state taxes. It's £329 over here.

Writing by Rik Henderson.