United Kingdom - Passport & Nationality - British Citizenship by Double Descent (PGF USA)
This is an instance where British nationality can be passed down two generations - that is, from a UK-born paternal grandfather. While the theory is complex, this solution broadly requires the following:
- Applicant born in a qualifying country
- Applicant born before 1988
- Father born in the United States of America
- Paternal Grandfather born in the UK
An additional requirement is that the applicant's grandfather was naturalised as a US citizen while he was still under the age of 18.