Historically, if a father was not married to a child's mother, he could not pass on his British nationality automatically to his child. This meant that if a child was considered "illegitimate" and had a British father, they could not acquire their citizenship unless the mother was British or settled. This was the case even if the child was born in the UK.

Whilst somewhat surprising, the entitlements owed to a person in the UK solely by virtue of having been born in the UK are limited. The concept of entitlement to citizenship through being born in a country is known as jus soli.

This concept was abolished in the legislation when the British Nationality Act 1981 came into force.

Although the current law is far more inclusionary than previous legislation, citizenship is not automatically acquired. Children of unmarried parents must therefore register for British citizenship by application.

This previous post covers the broader circumstances in which you may have a claim to British citizenship outside of the scope of children of unmarried parents.

Children Born on or After 1 July 2006

Unmarried fathers are able to pass on their British nationality to children born on or after 1 July 2006, subject to proof of paternity.

Defining Parents Under the British Nationality Act 1981

For individuals born on or after 1 July 2006, the legislation defines a person's mother as the person who gave birth to the child.

Under section 50(9) and (9A) of the British Nationality Act 1981, the definition of father is set out as:

  1. The husband, at the time of birth, of the woman who gives birth to the child, or
  2. where a person is treated as the father of the child under section 28 of the Human Fertilisation and Embryology Act 1990 or section 35 or 36 of the Human Fertilisation and Embryology Act 2008, that person, or
  3. where a person is treated as a parent of the child under section 42 or 43 of the Human Fertilisation and Embryology Act 2008, that person, or
  4. where none of paragraphs (a) to (ba) applies, a person who satisfies prescribed requirements as to proof of paternity.

Section 50(9A) was determined incompatible with human rights law in the case of R(K) v SSHD [2018].

As such, Section 7 of the Nationality and Borders Act 2022 amends this issue by providing a method for acquisition for those whose mother was married at the time of their birth to someone other than their biological father, who is a British citizen.

Proof of Paternity for Children of Unmarried Parents

Means of proving paternity, as necessary for when the mother was unmarried at the time of birth and circumstances ii and iii above, are set out in The British Nationality (Proof of Paternity) Regulations 2006.

These are:

  • The father being named on the child's birth certificate which must be issued within one year a child's birth (where the birth was registered before 10 September 2015)
  • DNA test report demonstrating the he is the natural father (this is not mandated)
  • Court order demonstrating that he is the natural father.

For surrogate mothers, specific guidance is set out here.

As such, children born on or after 1 July 2006 can acquire citizenship by virtue of their father's nationality, even if unmarried, if the stipulated evidence can be provided.

Children Born Between 1 January 1983 and 1 July 2006

Section 65 of the Immigration Act 2014 created new registration pathways to British citizenship in sections 4E-4J. These are provisions into the British Nationality Act 1981 and are only applicable to individuals born prior to 1 July 2006.

For children of unmarried parents born before 1 July 2006, the "legitimacy" of the child should be considered to see if British citizenship was acquired or should have been.

The following can be regarded as 'legitimate':

  • a child whose parents were married at the time of the birth
  • a child whose parents were not married at the time of the birth, but married at a later date – if that meant that the child was treated as having been legitimated by the marriage, according to the laws of the place where the father was domiciled
  • a child who was treated as legitimate by the laws of the country where the father was domiciled at the time of the birth, irrespective of whether the parents were married or not.

Domicile Relating to Legitimacy of Children of Unmarried Parents

It is therefore sometimes necessary to ascertain where someone was domiciled, the details of which are set out in this blog post.

If a father was domiciled outside the UK, it is necessary to check their laws. Some countries do not distinguish between legitimacy and illegitimacy in law. If this is the case, the individual is considered "legitimate".

Subsequent Legitimation of Children Under the British Nationality Act 1981

Section 47 of the British Nationality Act 1981 sets out that a subsequent marriage of parents can render an individual "legitimate" if the country in which the father was domiciled in at the time of birth legitimates the individual.

There is a degree of uncertainty as to what would happen to the individual's citizenship following a later annulment of their parents marriage or if their father's British citizenship was later void. It is likely that in these circumstances, the individual's citizenship will be determined ineffective but the mechanisms of registration or naturalisation can be used to restore it.

Parents' Void Marriages Under the Legitimacy Act 1976

If the parents' marriage is void, an individual may nonetheless have a claim to nationality under s1(1) of the Legitimacy Act 1976.

The requirements are that it can be determined that one or both of the individual's parents had reasonable belief their marriage is valid, under English law and the father was domiciled in England and Wales at the time of:

  • conception
  • the medical treatment to conceive the child
  • the marriage or civil partnership if it takes place between conception and birth (whilst the mother is pregnant).

The example given in the Guidance is that the above requirements are met, an individual's parents are in a polygamous/bigamous marriage at the time of birth, it is their father's second, third or subseuqent marriage and their father was domiciled in the England and Wales.

Process of Registering for British Citizenship

These routes are not automatic routes to acquisition. It would therefore be necessary to register for British citizenship using an application.

If you are successful in obtaining British citizenship using this route, the citizenship acquired will be British by descent if they would have automatically become British by descent had their parents been married.

Alternative Discretionary Routes to British citizenship for minors and adults

Beyond the routes discussed, there is also scope for the Secretary of State to use their discretion and grant citizenship to minors under s.3(1) BNA 1981.

Further, section 8 of the Nationality and Borders Act 2022 extends the discretionary powers available under s(3)1 BNA 1981 to adults. This discretionary power can be utilised where an individual would have had British citizenship had it not been for:

  • historical legislative unfairness,
  • an act or omission of a public authority, or
  • exceptional circumstances relating to the individual.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.