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Applying for British citizenship by naturalisation


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Naturalisation is the legal process by which a non-British adult becomes a British citizen. An application has to be made to the Home Office and if the criteria set out in the British Nationality Act 1981 are met then the application will be granted and the person can attend a ceremony to become a British citizen and obtain a Certificate of Naturalisation. Around 182,000 foreign nationals became British citizens in this way in the year ending September 2023.

The application is normally made and paid for online via the gov.uk website, although a paper form, Form AN, can still be used. At the time of writing the fee was £1,580, of which only £80 (the administrative cost for the citizenship ceremony) will be refunded if the application is refused.

The requirements for naturalisation include a set period of lawful residence in the United Kingdom, possession of permanent immigration status, passing the “good character” test, passing the “Life in the UK” test and taking an oath of allegiance to His Majesty the King at a formal citizenship ceremony. In this blog post we’re taking a quick look through these core requirements to explain what they mean and how the good character test is interpreted by the Home Office.

The Home Office has the legal power to waive some of these requirements but will not generally do so without being asked and without there being a good reason. Looking at the circumstances where the requirements might be relaxed in individual cases is beyond the scope of this blog post.

If you would like to take a look for yourself at the legal requirements in the British Nationality Act 1981, take a look at section 6 and Schedule 1. There is also internal Home Office guidance to caseworkers which includes further information about how the Home Office interprets and applies the law.

Qualifying period of residence in UK

Most people will need to live in the UK lawfully for at least five years before they can apply for naturalisation as a British citizen. There are different rules in the British Nationality Act 1981 for those who are married to a British citizen and those who are not: for those not married to a British citizen the period will usually be six years.

There are also rules on the maximum amount of time that a person can spend outside the UK during their qualifying residence period. These are referred to as absences from the UK.

If married to a British citizen

The British Nationality Act 1981 says that a person married to a British citizen can apply for naturalisation after three years of living in the UK lawfully (BNA 1981, Schedule 1, paragraph 3(a)). But the Act also requires a person married to a British citizen to have permanent immigration status before being able to apply (BNA 1981, Schedule 1, paragraph 3(c)). Since 2012 it has taken five years for the spouse of a British citizen to qualify for permanent status (called indefinite leave to remain). So, in effect, the period of residence is really five years even for spouses of British citizens, unless they manage to acquire indefinite leave to remain via some other accelerated route to settlement such as the Global Talent route.

If a person married to a British citizen somehow managed to get permanent status within three years of beginning residence in the United Kingdom, he or she would be eligible to apply for naturalisation at the end of that three-year period.

The maximum permitted number of full days absent from the UK for those married to a British citizen is 270 days in total during the three years leading up to the application for naturalisation, no more than 90 of which can fall during the final qualifying year.

If not married to a British citizen

The British Nationality Act 1981 says that a person not married to a British citizen can apply for naturalisation after five years of lawful residence (BNA 1981, Schedule 1, paragraph 1(2)(a)). But the Act also requires a person not married to a British citizen to have permanent immigration status and to have held it for at least one year before applying for naturalisation (BNA 1981, Schedule 1, paragraph 1(2)(c)). It takes most migrants five years to qualify to apply for permanent immigration status, meaning that in reality it will usually take six years before the person can apply for naturalisation.

The maximum permitted number of full days absent from the UK for those not married to a British citizen is 450 days in total during the five years leading up to the application for naturalisation, no more than 90 of which can fall during the final year.

Permanent immigration status

As we have said above, all applicants for naturalisation will usually need to hold permanent immigration status. For most people this will mean a status called indefinite leave to remain, often referred to as ILR. Indefinite leave to remain is sometimes referred to as “settled status”.

The technical language of the British Nationality Act 1981 actually refers to a person “not subject under the immigration laws to any restriction on the period for which he might remain in the United Kingdom”. There are some migrants who meet this requirement without formally being granted indefinite leave to remain, such as certain Commonwealth citizens and Irish nationals.

Physical presence in the UK

An odd quirk of naturalisation applications is that the applicant must have been physically present in the UK exactly three or five years prior to their application (depending on whether they are married to a British citizen or not). This is because of the wording used in Schedule 1 of the British Nationality Act 1981 to establish the qualifying period of residence:

that he was in the United Kingdom at the beginning of the period of three [or five] years ending with the date of the application…

This requirement of the legislation can now be waived at the Home Secretary’s discretion following amendments to the British Nationality Act 1981 introduced by the Nationality and Borders Act 2022. Discretion will only typically be exercised in the following circumstances:

  • the applicant was prevented from being in the UK because they had been removed from the UK, and the decision to remove them was later overturned
  • the applicant was incorrectly prevented from resuming permanent residence in the UK following an absence
  • the applicant is normally resident in the UK but there were exceptional reasons why they could not return from abroad at that time, such as illness, or travel restrictions due to a pandemic
  • the applicant is a current or former member of the armed forces (see the section on armed forces applicants)

If seeking discretion, an applicant will need to provide evidence to prove their claim.

Knowledge of language and life in the UK

All applicants for naturalisation must show sufficient knowledge of English, Welsh or Scottish Gaelic, and “sufficient knowledge about life in the UK”.

To pass the English language requirement, applicants will need to come from an English speaking country, have a degree taught in English, or pass an approved English language test. For the life in the UK element, the applicant must have passed the Life in the UK test.

There is discretion to waive the language and life in the UK requirement where it would be unreasonable to expect the applicant to fulfil it because of age or physical or mental condition. The language and life in the UK requirement will normally be waived where the applicant is aged 65 or over.

Intention to live in the UK

Those not married to a British citizen have to demonstrate an intention for their principal home to be in the UK.

Home Office guidance used to succinctly sum up this requirement as the need to show that the person had “thrown in their lot” with the United Kingdom. Evidence of a home and a life in the UK will generally be enough to discharge this requirement, though the Home Office may investigate further.

If a person is abroad or about to go abroad it may be important to explain this and to provide sufficient evidence to show that there is an intention to live in the UK. For example, caring for a person overseas who is ill or dying is likely to be a temporary absence and should not be treated as evidence that a person has no intention to live in the UK.

The good character requirement

The Home Secretary will only naturalise a person of “good character”. There is detailed guidance to Home Office caseworkers on what this means. Checks will be made in relation to criminal offences and financial solvency. Certain immigration and nationality decisions are now exempt from section 4 of the Rehabilitation of Offenders Act 1974. This means that it does not matter whether a conviction is “spent” when assessing good character.

The starting point of any good character assessment is criminality. For applications made on or after 31 July 2023, the Home Office will normally refuse an applicant if they:

• have received a custodial sentence of at least 12 months in the UK or overseas

• have consecutive sentences totalling at least 12 months in the UK or overseas

• are a persistent offender who shows a particular disregard for the law

• have committed an offence which has caused serious harm

• have committed a sexual offence or their details are recorded by the police on a register

If one of the above refusal categories is triggered, a caseworker can then go on to consider whether an “exceptional grant” is suitable if there are mitigating circumstances. Page 54 of the guidance sets out some examples considered to warrant an “exceptional grant”, but as the phrase suggests, these are likely to be exceptional situations only.

This first set of criminality thresholds is followed by a lesser set of criteria which can still trigger refusal. The wording of this set of criteria is clunky. Unlike above, the guidance starts by saying 

A person must be refused if they have:

• a custodial sentence of less than 12 months

• a non-custodial sentence or out-of-court disposal recorded on their criminal record

This is qualified however, by the next part which says:

and you are not satisfied, on the balance of probabilities, that they are of good character. [Emphasis added].

Caseworkers are directed to apply the balance of probabilities in the following way:

An assessment of whether or not a person is of good character on the balance of probabilities, must take account of all available information concerning the applicant’s character, weighing any negative factors around criminality against mitigating factors such as contributions a person has made to society or any significant proportions of a person’s life spent not offending.

You must consider the individual circumstances of the case; what may be appropriate for one case will not be appropriate for another. Each application must be carefully considered on an individual basis on its own merits, giving consideration to the (non-exhaustive) list of factors below:

The guidance then lists and elaborates on the following factors which must be weighed in the balance:

  • Length of time since offences occurred
  • Number of offences
  • Period over which offences were committed
  • Seriousness of the offence
  • Any escalation in seriousness of offences
  • Nature of offences
  • Age at date of conviction
  • Exceptional or other circumstances in the person’s life when they committed the offences
  • Other positive mitigating factors showing genuine and meaningful attempts to change behaviour, such as engagement with rehabilitation programmes or voluntary work.

Conduct that does not amount to a criminal offence (or which was not prosecuted or did not lead to a conviction) can also lead to refusal of a naturalisation application on character grounds. Other aspects of the good character test include financial soundness, notoriety, war crimes and terrorism, and past immigration offending.

The Home Office is obliged by law to consider positive evidence of good character which is submitted with an application, although this does not mean the Home Office is obliged to grant such an application.

Citizenship ceremonies

Sections 42 to 42B and Schedule 5 of the 1981 Act provide that anyone over the age of 18 who acquires British citizenship, whether by registration or naturalisation, must do so at a public ceremony and is required to take the oath and pledge of allegiance. Ceremonies are normally held in groups and normally take place at the local authority closest to the applicant’s home address. People can invite guests. A fee is payable and this fee makes up a proportion of the naturalisation application fee.

In exceptional circumstances an exemption may be made for any or all of the following:

  • the requirement to attend a citizenship ceremony
  • the requirement to make an oath of allegiance and pledge
  • the time limit for attending a ceremony

Normally a person seeking naturalisation has a period of three months to attend a citizenship ceremony. Due to the coronavirus pandemic this period was extended to six months, and the first ever virtual citizenship ceremony took place on 20 July 2020.

Challenging nationality decisions

There is no right of appeal to a court against refusal to grant nationality. There is however a mechanism similar to administrative review where a formal reconsideration request can be made on Form NR. An application for reconsideration carries a fee.

Ultimately, if that is refused, the only remedy would be judicial review. Some applications for judicial review of naturalisation decisions have occasionally succeeded but generally it is very hard to challenge Home Office decisions in this particular area of law because the legislation gives the Home Office a lot of discretion about how to make decisions.

For more information, you can take our course on naturalisation.

This article was updated by John Vassiliou in February 2024.

Module 1What is naturalisation?
Unit 1What is naturalisation? 
Module 2Residence requirements and intention to settle
Unit 1Residence requirements for naturalisation 
Unit 2Free of immigration time restrictions: ILR or settled status 
Unit 3Length of residence: spouse or civil partner of a British citizen 
Unit 4Length of residence: non-spouses 
Unit 5Physical presence in UK at start of qualifying period 
Unit 6Breaches of immigration law in the qualifying period 
Unit 7Intention to settle 
Module 3Good character
Unit 1Introduction 
Unit 2Criminal convictions 
Unit 3War crimes, terrorism and other activities contrary to the public good 
Unit 4Financial soundness and notoriety 
Unit 5Deception or dishonesty 
Unit 6Immigration issues 
Unit 7Dealing with the guidance in practice 
Unit 8Exceptions to the good character requirement 
Module 4Age and the knowledge of language and life tests
Unit 1Age 
Unit 2Life in the UK test 
Unit 3Knowledge of English 
Module 5Applying for and getting citizenship
Unit 1Application process 
Unit 2Oath and citizenship ceremony 
Unit 3Bringing a legal challenge 
Unit 4Feedback and final quiz 
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Colin Yeo

Immigration and asylum barrister, blogger, writer and consultant at Garden Court Chambers in London and founder of the Free Movement immigration law website.