TCM0128020 | Eligibility - residency and immigration: Immigration control - not subject to (Info)
From HM Revenue & Customs · Tax Credits Manual
You should assume that the people outlined below aren’t subject to immigration control.
British passport holders and people with dual nationality, provided their passport is marked with one of the following
British Citizen
Holder is entitled to re-admission to the United Kingdom (UK)
Holder has the right of abode in the UK
holders of another passport marked with one of the following
British Citizen
Given leave to enter the UK for an indefinite period
Given leave to remain in the UK for an indefinite period
There is at present no time limit on the holders stay in the UK
people who have been granted refugee status with either unlimited or limited leave to remain in the UK
people who have been granted exceptional leave to remain in the UK
Nationals of Switzerland and of states that belong to the European Union (EU)