Until how old can a child of a naturalized citizen get citizenship as a result of family reunification?
<p>Bob is a citizen of a Member State B of the EU and is naturalized to be a citizen of the UK after the birth of his child. Bob had been living in the UK for 5 years before Brexit started, and has been living there ever since. He will soon receive citizenship.</p>
<p>He decides that he wants his less than 16-years-old child (born in Member State B outside the UK as his dad) to be a UK citizen too who otherwise lives with Bob’s divorced wife in Member State B.</p>
<p>What are the prerequisites? Does the child have to move to the UK, and if so, for how long?</p>

<p>According to <a href="https://www.citizensadvice.org.uk/immigration/getting-british-citizenship-for-children" rel="nofollow noreferrer">Citizens' Advice</a>, the child must live in the UK to be eligible for registration as a British citizen.  If the child is over 13, the period of residence must be at least two years.  However, in this case, the child appears not to be eligible, because the child's other parent resides abroad and is not a British citizen:</p>
<blockquote>
<p>You can apply to register your child as British if one of their parents is British or applying to become British.</p>
<p>Your child’s other parent must either be British or settled in the UK. If their other parent has an immigration status that will lead to settlement, your child’s application might still be successful.</p>
</blockquote>
<p>If the child cuts ties with Bob's former wife, however, this ineligibility disappears:</p>
<blockquote>
<p>If you’re British and your child doesn’t have regular contact with their other parent, the other parent’s immigration status doesn’t matter.</p>
</blockquote>
<p>The child could move to the UK as Bob's dependent child (probably under the EU settlement scheme), and then apply for naturalization after turning 18.  This seems to be the only route where the child would derive some advantage from Bob's status in the UK.</p>

united-kingdom citizenship