If the phone is carrier blacklisted in the U.K. it won't work there. If the UAE does not share the U.K. Blacklisting database (which it most likely does not) then it would work there, or anywhere else that doesn't use the U.K. Blacklist.
Carrier blackilisting is not universal. If a device is stolen in one country, and reported and blacklisted there, it will often end up being sold in another country to avoid the blacklist.
For example, in the USA all carriers share a blacklist, and that in turn is shared with carriers in Canada and Mexico. But outside of those three countries, the USA universal blacklist won't have any affect elsewhere.
They are not a supported carrier in the UAE (Wireless carrier support and features for iPhone in the Middle East - Apple Support) although they are listed as an Authourized reseller in Dubai so that's a bit odd. Might want to go back and talk to them about it.
Yeah I just ran a checkmend report. It is blocked. I bought the phone from Axiom Telecom here in Dubai. Seems they sold me a dodgy phone and they are supposed to be reputable company
my iphone works fine in the UAE where purchased but when in uk says "Phone no allowed". apple tell me its blocked which. means it ahould not work in the UAE but it does
