In this post we discuss the eligibility requirements to naturalise as a British citizen.

Naturalisation is the process which is used by foreign national adults to apply to become British citizens, usually some time after obtaining Indefinite Leave to Remain (ILR, also known as ‘settlement’). This is different from registration as a British citizen which is subject to a different set of rules.

Our Milla Walker takes a look at the process.

Naturalisation requirements

The requirements vary depending on whether you are married to a British national or not.

If you are married to a British national, you need to have been lawfully resident in the UK for at least 3 years prior to making your application, and to hold ILR.

If you are not married to a British national, you need to have been lawfully resident in the UK for at least 5 years prior to making your application, and you need to have held your ILR for at least 12 months before applying for naturalisation.

Apart from these differences relating to your marital status, the remainder of the requirements are the same.

Be 18 or over and of sound mind

This means that you have capacity to make your own decisions. If you are under 18, you may be entitled to register as a British citizen.

Satisfy Knowledge of Language and Life in the UK requirement

In order to meet this requirement, you must show that you have passed the Life in the UK, and speak English to the required level.

Life in the UK test

Unless exempt, all applicants for naturalisation must pass the computer based, obscure pub trivia Life in the UK Test

The pass mark is 75%, and (we would suggest) you need to actually prepare to be able to pass first time around. There are study materials available.

You can take the test as many times as you like, if that is your sort of thing, but each attempt will set you back a further £50.

Pensioners (over 65s) are exempted from this requirement, although younger adults can be exempted if they can provide medical evidence to demonstrate a long-term inability to sit or pass the test.

English language

Unless you meet the requirement in another prescribed way (see below), applicants must provide an approved English language test certificate or electronic reference demonstrating adequate English language skills in Speaking and Listening.

The test needs to be at a level of at least B1 CEFR and needs to be completed with one of the providers approved by UKVI, e.g. Trinity College London, or IELTS SELT.

Some applicants are exempt from this requirement where for example an individual has completed a degree level course in the UK, or the Home Office accepts that they come from a country on their list of ‘majority English speaking countries’. The list is mainly made up of Caribbean and Antipodean states, as well as the USA.

If you have already met these requirements for your ILR application, you don’t need to do them again.

Free of immigration time restrictions

This means showing that you have Indefinite Leave to Remain (ILR) or settlement (or a small number of other types of status e.g. right of abode), and, if you are not married to a British national, that you have held that status for at least a year at the time you make the application.

Residence requirements

In broad terms, the residence requirements refer to the 3 or 5 year ‘qualifying period’ leading up to the date of your application that is considered by the Home Office in citizenship applications. You need to have:

Been physically present in the UK on the date which is at the start of the qualifying period

For example, if you apply on 1 January 2020, you need to have been physically present in the UK on 2 January 2015 (if applying via the 5 year qualifying period). In the event that an individual falls foul of this rule, discretion can be exercised in certain circumstances, as set out in the Home Office caseworker guidance document.

Not been outside of the UK for more than 450 days (5 yr qualifying period), or 270 days (3 yr period)

In probably the most painful part of the process for the majority of applicants, you will be expected to prove that you meet this requirement by providing details of every trip outside of the UK during the qualifying period. The form currently allows for 30 trips to be entered, with any additional trips to be provided by way of a covering letter.

Not outside UK for more than 90 days in 12 months prior to the submission of the application

In addition to the rule relating to the full qualifying period, there is an additional absences requirement relating to the 12 months running up to the date of the application.

There are some exceptions to these residence requirements, so if you are close to the wire we would always suggest that you obtain legal advice before submitting your application, for example by having a lawyer review it via a one-off consultation.

Good character

This requirement can pose problems for a large number of people as it is not only limited to criminal convictions. For example, as per the relevant policy guidance, the Home Office can examine any financial irregularities in your background by liaising with HMRC. Failure to pay the proper amount of tax can be considered an indication of bad character.

The Home Office will also look back over a 10 year period to find any immigration related reasons why you could be considered not to be of good character.  Immigration related matters leading to a good character refusal could include overstaying your visa, entering the UK illegally or working here when you have no permission to do so.

Where you have any concerns about how this requirement could apply to you, and to avoid losing your application fee, it is really worth getting professional advice. We can provide one off consultations to answer questions about this requirement, and advise you on your application more generally.


One of the criteria which many people don’t know much about is the requirement to have two referees to support your application.

Each referee has to agree to provide their details to the Home Office including their passport number and contact details, and they also have to complete and sign a form that is downloaded from the UKVI website.  Not anyone can be a referee.  There is guidance available online in the Home Office’s policy document here (page 10).

Application process

Most naturalisation applications are made online via the UK Visas and Immigration website.  The application form itself can be saved and returned to any number of times before you submit it, and once it is submitted, you can download and save it to your device as a PDF.

Once the online form has been submitted and the fee paid by credit/debit card, you will be given a list of required documents, and you will have to use your Unique Application Number generated by the Home Office site to log into a separate website (UKVCAS) in order to book a biometric appointment and upload your supporting documents.

The supporting documents will include your passport and BRP, proof of your residence in the UK and other paperwork, depending on your circumstances.

Cost of naturalisation

Citizenship in the UK does not come cheap.  Comparatively, the UK ranks globally as one of the most expensive countries in which to naturalise.

In 2021, the cost of the application in terms of the Home Office fee alone is £1,330 (inclusive of the required citizenship ceremony fee (£80)), but applicants are also required to pay £19.20 to enrol their biometrics for the purpose of the application, and the Home Office’s commercial partners may also try to slip in additional charges for earlier or more convenient biometric appointment dates.

Ancillary costs may include taking the Life in the UK Test (£50 per attempt) and the English language test (£150).

The rub is that if you make a mistake on your application, or if you cannot satisfy any of the Home Office’s eligibility requirements, your application will be refused and, in most circumstances, none of the huge fee will be refunded (apart from the £80 ceremony fee).

As a result, it is essential to get your application right first time. If you would like to have the peace of mind that your application has been fully prepared by qualified and expert nationality solicitors, contact us to arrange an appointment.