CBTM10040 | Residence and Immigration: Residence - Circumstances in which a child or qualifying young person is to be treated as being in Great Britain or Northern Ireland
From HM Revenue & Customs · Child Benefit Technical Manual
Child Benefit (General) Regulations 2006, regulations 21 & 25
For the purposes of the Acts, a child or qualifying young person who is temporarily absent from Great Britain or Northern Ireland (as the case requires) is treated as being there for
the first 12 weeks of absence
or
any period due to
receiving full time education at a school or college in another EEA state or Switzerland
or
being on an educational exchange visit made with the written approval of the school or college usually attended
or
being absent for the specific purpose of being treated for a mental or physical illness which commenced before the absence began
or
being in Northern Ireland or Great Britain (as the case requires).
If a child is born when the mother is temporarily absent from Great Britain or Northern Ireland in any of the circumstances above, entitlement to Child Benefit can begin from the week following the date of birth until the end of the 12 week period beginning with the first week of the mother’s absence.