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New law significantly expands possibilities for claiming British citizenship through a grandparent


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A raft of changes to nationality law came into force a few weeks ago. I covered the changes at a high level on my own firm’s website (shameless plug), but wanted to write in more depth about the new section 4L, which opens up tantalising possibilities for securing British citizenship through UK ancestry. In this piece I’ll cover how section 4L works, why it’s there, what the guidance says, and some scenarios not in the Home Office guidance.

Section 4L of the British Nationality Act 1981 was brought into force on 28 June 2022, alongside the publication of an application form and guidance for applicants and separate guidance for caseworkers at the Home Office. It was inserted into the 1981 legislation by section 8 of the Nationality and Borders Act 2022. This is what it says:

Acquisition by registration: special circumstances

(1) If an application is made for a person of full age and capacity (“P”) to be registered as a British citizen, the Secretary of State may cause P to be registered as such a citizen if, in the Secretary of State’s opinion, P would have been, or would have been able to become, a British citizen but for—

(a) historical legislative unfairness,

(b) an act or omission of a public authority, or

(c) exceptional circumstances relating to P.

(2) For the purposes of subsection (1)(a), “historical legislative unfairness” includes circumstances where P would have become, or would not have ceased to be, a British subject, a citizen of the United Kingdom and Colonies or a British citizen, if an Act of Parliament or subordinate legislation (within the meaning of the Interpretation Act 1978) had, for the purposes of determining a person’s nationality status—

(a) treated males and females equally,

(b) treated children of unmarried couples in the same way as children of married couples, or

(c) treated children of couples where the mother was married to someone other than the natural father in the same way as children of couples where the mother was married to the natural father.

(3) In subsection (1)(b), “public authority” means any public authority within the meaning of section 6 of the Human Rights Act 1998, other than a court or tribunal.

(4) In considering whether to grant an application under this section, the Secretary of State may take into account whether the applicant is of good character.”

Registration will make the person a British citizen “otherwise than by descent”.

This blog concentrates only on ancestral claims based on historical legislative unfairness. It does not cover section 4L applications based on acts and omissions of public authorities, or exceptional circumstances generally.

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Why we needed this: gaps in sections 4C / 4E-J

There were already provisions in the 1981 Act dealing with historical legislative unfairness. These tackle the present-day effects of past discrimination against women or “illegitimate” children:

  • Section 4C gives someone born before 1 January 1983 the right to register as British if (roughly) they would have been a British citizen, had their mother been able to pass on her British nationality in the same way as a man.
  • Sections 4E-4J give people the right to register if (roughly) they would have been, or could have become, a British citizen had their natural father been married to their mother at the time of their birth.

But there are gaps in these provisions.

  • They only remedy discrimination as it affected citizenship transmission from a parent. There is no remedy for the present-day effects of discrimination in the grandparental generation or higher.
  • They do not work for claims based on a connection to a British overseas territory. (This is now addressed by newly added sections 17A-G.)
  • They cannot be applied iteratively. In other words, you can’t remedy the combined effects of different types of discrimination on the same family history.

As we shall see, the new legislation is particularly significant for certain people with British grandparents.

How does section 4L fill the gaps?

Section 4L does not define historical legislative unfairness. Subsection (2) simply gives examples of what it covers at a minimum. But the guidance tells us more. It sensibly expands “unfairness” as potentially including any legislation which discriminates on the basis of a protected characteristic: age, disability, gender reassignment, marriage and civil partnership, pregnancy and maternity, race, religion or belief, sex and sexual orientation.

The guidance also references the possibility of applying for citizenship through grandparents:

… in terms of people with British grandparents, Parliament’s intention was that citizenship will normally only be passed on for one generation born overseas, and section 4L is not intended to change that, although you must consider each case on its merits and assess if there are exceptional circumstances.

It’s true that “double descent” (passing on British citizenship to the second generation born outside British territory) is not the norm. But it was and is possible, and the governing provisions certainly contained discrimination. Unfortunately, the guidance instructs applicants to set out “the legislation and section you think was unfair” – not very helpful to those without lawyers.

The Home Office has included a set of case studies, but they don’t include any cases in which double descent arguments would actually work – the relevant two case studies are negative (what will not work). In one of the examples, Rachel has a UK-born grandmother and argues that her mother would have moved to the UK if she had had UK citizenship. This is not accepted as a reason to allow Rachel to register under section 4L, as it relies on a “hypothetical”, but the reasoning is not too clear. Is Rachel’s argument weak because it relies at any level on how her mother would have acted in a counterfactual scenario? Or is the issue a lack of evidence? What if Rachel’s mother had made an application to settle in the UK before her birth and had been refused?

Case studies on invoking section 4L

So what scenarios will work? I won’t go through every possible case, but here are some examples.

Example A

  • A’s paternal grandmother was born in the UK.
  • A’s other grandparents, and parents, were born before 1949 in Trinidad.
  • A was born in Trinidad between 1949 and 1962.

In this example, A acquired Citizenship of the UK and Colonies (CUKC) by birth in a colony, but would have lost it when Trinidad and Tobago became independent on 31 August 1962. The Trinidad and Tobago Independence Act 1962 (the UK law dealing with independence) contained historical legislative unfairness. Section 2(3) provided for Trinidadians to retain CUKC status if they, their father, or their father’s father was born, registered or naturalised in the UK or a remaining colony; the status of A’s grandmother as a person born in the UK did not help. 

If in the same scenario A’s paternal grandfather had been born in the UK, A would be a British citizen today. This type of discrimination was a feature of all independence legislation in the 1949-82 period.

Example B

  • B’s paternal grandfather, G, was born in the UK. While stationed overseas as a British army officer between 1949 and 1982, G had a son, B’s father, born out of wedlock. G was never married to the mother (B’s paternal grandmother). He retired to the UK and has now died.
  • B himself was born outside the UK after 1983.

So B’s father was born “illegitimate”, as nationality law put it at the time. Therefore B’s father never acquired CUKC status. G, although his natural father, was never regarded as the legal father under section 32(2) of the British Nationality Act 1948.

If B’s paternal grandparents had been married at the time of B’s father’s birth, then B’s father would have become a CUKC. On commencement of the 1981 Act, B’s father would under section 14(2) have become a British citizen “otherwise than by descent”. This is because G was in overseas Crown service at the time of his son’s birth, having been recruited in the UK (this is assumed for military officers). B would then have become a British citizen at birth.

Example C

  • C was born in South Africa between 31 May 1962 and 31 December 1982.
  • C’s grandmother was born in the UK but there is no other ancestral connection to the UK.

In this scenario, neither of C’s parents can be British from birth: the grandmother was unable to pass on her citizenship to a child born outside the UK because of discriminatory citizenship laws.

Had the parent been a CUKC at the time of C’s birth, then C would have had the option of consular registration under section 5(1)(b) of the 1948 Act. (When C was born, South Africa was a “foreign” country as it was outside of the Commonwealth from 31 May 1962 onwards.) So C was prevented from becoming a British citizen by gender discrimination.

This argument relies upon the rule in Romein [2018] UKSC 6 being applied to section 4L cases in the same way as for applications under section 4C. Given the reasoning of Lord Sumption in the judgment, and the fact that the Home Office has not only accepted it but built the Romein assumption into primary legislation, this seems reasonable.

There is some bonus complexity in terms of how recently C can be born and still rely on this argument. Romein was a decision relating to section 4C, which has built into it a requirement that the applicant is born before 1983. But transmission of British nationality by registration continued for five years after commencement of the 1981 Act, until 31 December 1987. So there is an argument that example C can be extended to a person born in a foreign country before 1 January 1988.

If instead it was C’s grandfather who had been born in the UK, it is unclear whether there would be a section 4L case. C would have had an actual opportunity of consular registration, which was not exercised.  Against this, it might be argued that an additional opportunity (at the initiative of a different parent) was not present because of gender discrimination.


Section 4L opens up significant possibilities for claiming British citizenship, potentially including those born in a foreign country before 1988 with a UK-born grandmother and many other cases. This is not readily apparent from the Home Office guidance, which asks people applying for citizenship on the basis of historical discrimination to set out the specific legal provisions on which they rely. As the examples I have given show, those with UK-born grandparents may well have strongly arguable claims — even if they need legal advice to make them stick.

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Alexander Finch

Alexander Finch

Alexander Finch is a Senior Manager and Solicitor at Fragomen since 2015. He qualified in 2010 initially at a legal aid practice focusing on asylum and human rights claims. He currently manages the private client team in Fragomen’s London office and has a particular interest in British nationality law.