It’s a United Kingdom..., so we say "a United Kingdom resident", "a United Kingdom company", "a United Kingdom national", etc.
It’s a United Kingdom..., so we say "a United Kingdom resident", "a United Kingdom company", "a United Kingdom national", etc.
He is a United Kingdom citizen resident in London.
He is an United Kingdom citizen resident in London.
Remember, we use "a" before words that begin with a consonant sound. Since the first letter of the word "United" (U) sounds like "you", we use the article “a”.
She is the director of a United Kingdom company.
Similarly, we say a UK company, a United Nations official (or a UN...), a UNESCO, or a United States citizen.
A partial list of words that also begin with the vowel “u” but take the indefinite article “a”: