Here's some more information from http://www.hmrc.gov.uk/childbenefit/arrivals-to-uk.htm
If you're subject to 'immigration control'
You may not be able to get Child Benefit if you're subject to 'immigration control'. Immigration control means either:
- the Home Office says you have permission to stay in the UK (known as ‘leave to enter or remain’) but this permission is given to you on the grounds that you don’t claim some benefits, tax credits or housing help paid by the UK government (known as ‘recourse to public funds’)
- you need permission to stay in the UK – again known as ‘leave to enter or remain’- but you don’t have it
Sometimes if you’re subject to immigration control you might still be able to claim Child Benefit, for example if you're from a country with which the UK has a social security agreement that covers Child Benefit.
