How British citizenship by descent works
The eligibility rules for British citizenship by descent, in plain English — who may qualify, what disqualifies, and the legal regimes over time, each cited to its primary statute.
Who may qualify
A qualifying path — via the passport direct route
Requirements
ALL of the following
the applicant must be the parent of the qualifying ancestor.
- relationship:
- parent
the qualifying ancestor has a qualifying british otherwise than by descent (confirmed).
- confirmed:
- true
the qualifying ancestor must have held british citizenship at the moment the applicant was born, passing it down the line by descent.
- required citizenship:
- british
Primary sources
- § British Nationality Act 1981, s.2 — child born abroad to a British citizen otherwise than by descent is British by descent (https://www.legislation.gov.uk/ukpga/1981/61/section/2)
A qualifying path — via the declaration route
Requirements
ALL of the following
the applicant must be the parent of the qualifying ancestor.
- relationship:
- parent
the qualifying ancestor must have held british citizenship at the moment the applicant was born, passing it down the line by descent.
- required citizenship:
- british
the applicant must have been physically present in united_kingdom for at least 3 years.
- country:
- united_kingdom
- years of presence required:
- 3
the applicant has a qualifying s3 5 both parents uk resident (confirmed).
- confirmed:
- true
the applicant has a qualifying age at application (under 18).
- under 18:
- true
Primary sources
- § British Nationality Act 1981, s.3(5) — registration where the child and both parents have 3 years' ordinary UK residence ending on the application date; confers British citizenship OTHERWISE THAN BY DESCENT (https://www.legislation.gov.uk/ukpga/1981/61/section/3)
A qualifying path — via the declaration route
Requirements
ALL of the following
the applicant must be the parent of the qualifying ancestor.
- relationship:
- parent
the qualifying ancestor must have held british citizenship at the moment the applicant was born, passing it down the line by descent.
- required citizenship:
- british
the qualifying ancestor must have been physically present in united_kingdom for at least 3 years, with that presence ending before the descendant's birth.
- country:
- united_kingdom
- years of presence required:
- 3
- presence must end before:
- descendant_birth
the applicant has a qualifying s3 2 grandparent otbd (confirmed).
- confirmed:
- true
the applicant has a qualifying age at application (under 18).
- under 18:
- true
Primary sources
- § British Nationality Act 1981, s.3(2) — registration where the British-by-descent parent had a qualifying 3-year UK residence period ending before the child's birth; confers British citizenship BY DESCENT (https://www.legislation.gov.uk/ukpga/1981/61/section/3)
A qualifying path — via the declaration route
Requirements
ALL of the following
the applicant has a qualifying born before 1983 (confirmed).
- confirmed:
- true
the applicant has a qualifying s4c maternal line gender exclusion (confirmed).
- confirmed:
- true
the qualifying ancestor must have held british citizenship at the moment the applicant was born, passing it down the line by descent.
- required citizenship:
- british
Primary sources
- § British Nationality Act 1981, s.4C (inserted by the Nationality, Immigration and Asylum Act 2002 s.13; ss.4C(3)-(3D) substituted by the Borders, Citizenship and Immigration Act 2009; last amended by the Nationality and Borders Act 2022 s.6(2)) — registration for persons born before 1983-01-01 who would have been British but for pre-1983 maternal-line gender discrimination (https://www.legislation.gov.uk/ukpga/1981/61/section/4C) [GB-01]
A qualifying path — via the declaration route
Date keying
- In force from 2025-07-22 onward — keyed on the assessment date, not on anyone's birth.
Requirements
ALL of the following
the applicant has a qualifying irish citizen (confirmed).
- confirmed:
- true
the applicant must have been physically present in united_kingdom for at least 5 years.
- country:
- united_kingdom
- years of presence required:
- 5
Primary sources
- § British Nationality Act 1981, s.4AA (inserted by the British Nationality (Irish Citizens) Act 2024, commenced 2025-07-22) — simplified registration for Irish citizens with 5 years' UK residence (https://www.legislation.gov.uk/ukpga/2024/19)
Cases that need individual review
Needs individual review
Date keying
- In force from 2022-06-28 onward — keyed on the assessment date, not on anyone's birth.
Requirements
ALL of the following
the applicant has a qualifying s4l historical unfairness claim (confirmed).
- confirmed:
- true
Primary sources
- § British Nationality Act 1981, s.4L (inserted by the Nationality and Borders Act 2022, in force 2022-06-28) — discretionary registration for historical legislative unfairness / public-authority acts or omissions / exceptional circumstances; requires case-by-case Home Office assessment
Needs individual review
Requirements
ALL of the following
the applicant must be the grandparent of the qualifying ancestor.
- relationship:
- grandparent
the applicant has a qualifying commonwealth citizen (confirmed).
- confirmed:
- true
the applicant has a qualifying age at application (meets min 17).
- meets min 17:
- true
the applicant has a qualifying work intention uk (confirmed).
- confirmed:
- true
ANY of the following
The qualifying ancestor must have been born in united kingdom.
- territory:
- united_kingdom
The qualifying ancestor must have been born in ireland pre 1922 between any earlier date and 1922-03-31.
- territory:
- ireland_pre_1922
- window end:
- 1922-03-31
the qualifying ancestor has a qualifying birth location (uk registered vessel).
- uk registered vessel:
- true
Primary sources
- § UK Immigration Rules — UK Ancestry visa (Appendix Ancestry): Commonwealth citizen aged 17+, intending and able to work in the UK, with a grandparent born in the UK / Channel Islands / Isle of Man, OR in what is now Ireland before 1922-03-31, OR on a UK-registered ship or aircraft (https://www.gov.uk/ancestry-visa/eligibility)
See how these rules apply to your family
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