Yes it can work. But this will also depend on what modules you are using. Let me explain, let's say you purchased a 890W from the US. You have to specify from your vendor that the router and the AP will be installed in the UK so your AP will be shipped with the correct regulatory domain.
Another example is when you have E1 or T1 modules. UK uses E1 so I don't know what's going to happen if you purchased T1 modules from your US vendor and ships them to the UK.
However, in some countries (not sure in the UK), the shipper or the recepient could be liable to pay import duties.