Increasingly, clients are turning to us for advice about British citizenship. Whether this is to do with the looming Brexit deadline, or sparked by a New Year’s resolution to get your immigration affairs in order (?!), it’s not clear.

Regardless of your motivation for becoming British (which my colleague once creatively likened to losing your virginity), this blog summarises the key routes under which the hallowed ‘British citizen’ status can be acquired – or indeed, how you might have already inadvertently acquired it!


Before getting into the nitty-gritty of the law, we need to get to grips with the following terminology relating to citizenship:

  • British citizens ‘by descent’ – this is a ‘weaker’ form of citizenship, as it means the person’s British nationality cannot generally be passed on to their children. A person is British ‘by descent’ if they have been passed their citizenship through a parent and were not born in the UK (i.e. have not otherwise acquired it through some action of their own);
  • British citizens ‘otherwise than by descent’ - this is a ‘stronger’ form of citizenship, since citizens ‘otherwise than by descent’ can pass their British nationality on to their children. Usually, British citizens otherwise than by descent have acquired citizenship through their own right – for example, those who’ve acquired citizenship through naturalisation (see below), who were born in the UK, or who have registered as British.


There are two key routes for naturalisation – both of which are incumbent upon a person having spent a prescribed amount of time in the UK. These ‘routes’ can be found in sections 6(1) and 6(2) of the British Nationality Act 1981 (the Act). The key distinction between these routes dictates how long you have to wait after obtaining Indefinite Leave to Remain (ILR), Permanent Residence (PR) or Settled Status (SS) before you can apply to naturalise.


The key requirements under this route are as follows: 

  • You have held ILR, PR or SS for 12 months (i.e. been “free from immigration restrictions”); 
  • You have not spent more than 450 days outside the UK during the past five years; 
  • You were physically in the UK on the day five years before the date of the application (i.e. if you submit an application on 5 January 2020, you must have been physically present in the UK on 6 January 2015); and 
  • You have not spent more than 90 days outside the UK in the 12 months preceding the date of the application.  


Under this route, there is no requirement to wait 12 months after obtaining ILR, PR or SS.  You will become eligible to apply for naturalisation immediately after being granted one of the above ‘settled’ statuses, as long as you are married to or in a civil partnership with a British citizen, and can meet the following additional criteria (NB this route does not apply to unmarried partners): 

  • You have not spent more than 270 days outside the UK during the past three years; 
  • You were physically in the UK on the day three years before the date of the application; and 
  • You have not spent more than 90 days outside the UK in the 12 months preceding the date of the application. 

For both routes, you must also be able to evidence that:

  • You are of good character (see my colleague’s blog here for more detail);
  • You have sufficient knowledge of the English language and have passed the ‘Life in the UK’ test;
  • It is your intention to make the UK your principal home; and
  • You have not been in the UK in breach of immigration laws during the qualifying period. In a recent decision from the Court of Appeal (R (Al-Enein) v. Secretary of State for the Home Department [2019] EWCA Civ 2024), it was confirmed that although the legislation explicitly states that applicants must not have breached immigration laws during the three or five year qualifying residency period, it is lawful for the Home Office to refuse an application if the applicant has breached immigration laws within the last 10 years – as per the Home Office good character guidance.

Importantly, EU citizens who apply for SS under the EU Settlement Scheme would not have been required to disclose their absences as part of their application, or to demonstrate that they have been exercising Treaty Rights during their time here. They are only required to show that they have not had absences of over six months in a 12 month period, unless those absences were for an important reason. It is expected that this could cause issues for EU nationals wishing to naturalise who have spent significant periods outside the UK. EU applicants should also bear in mind that they may also be asked to provide additional evidence about their exercise of Treaty Rights that led to the grant of their PR/SS.

Once you have received your Certificate of Naturalisation, you can then use this to apply for your first British passport.

Automatic Acquisition

If you have automatically acquired British citizenship, there is no need to register as British before applying for a passport.


If you were born in the UK and, at the time of your birth, one of your parents was British or otherwise ‘settled’ in the UK (i.e. had ILR, PR or SS), you will automatically have been born British ‘otherwise than by descent’, and can apply for a passport without having to register.  

For individuals born to EU citizens, the position for automatic acquisition for those born in the UK is slightly different: 

  • A child born in the UK before 2 October 2000 to an EEA national parent is automatically British if the parent was exercising treaty rights at the time of birth; 
  • A child born in the UK between 2 October 2000 and 29 April 2006 to an EEA national parent is not usually British, but can be registered if the mother or father subsequently acquires PR or SS (see below); 
  • A child born in the UK on or after 30 April 2006 to an EEA national who exercised treaty rights for five years (and therefore acquired PR or SS) before the child’s birth is automatically British.  

See the table here for further information.  


If you were born outside the UK and one of your parents is British otherwise than by descent, you will have automatically acquired citizenship by descent and can automatically apply for a British passport.  However, if you are able to do so, it is advisable to register under one of the following routes, to obtain citizenship otherwise than by descent.

Registration of Children

Registration under any of the following routes (other than the discretionary route) leads to British citizenship otherwise than by descent. Importantly, applications to register as British must be submitted before the applicant’s 18th birthday, and applicants over the age of ten must also be able to demonstrate that they are of good character – although, as my colleague mentioned in a previous blog, the Parliamentary Human Rights Committee has expressed “deep concern” for children as young as ten being denied their right to claim British nationality on the basis of this good character requirement.

Discretionary Applications

Under section 3(1) of the Act, the Secretary of State has a broad discretion to register any child as British if she ‘thinks fit’. The Home Office guidance states that caseworkers must “consider each case on its merits”, including an assessment of all relevant factors, as well as public interest considerations. Typically, applicants would be required to evidence that there are exceptional, compelling or compassionate circumstances justifying citizenship in order to make a successful application.

If the father or mother was a British citizen at the time of the child’s birth, registration under this discretionary route will lead to British citizenship by descent. In all other cases, discretionary applications will lead to British citizenship otherwise than by descent.