Most adults living in the UK who have acquired indefinite leave to remain for at least 12 months can apply for naturalisation. If naturalisation is acquired successfully, they can apply for a British passport, which is one of the strongest passports in the world.
You can live outside the UK for as long as you want and come back without any restrictions. The UK also offers dual citizenship, which means that you do not need to give up your citizenship of your home country. 

Eligibility for UK Citizenship 

Millions of people want to make the UK their home. But this is not possible. However, those who are eligible can apply for UK citizenship. There are different ways to become a British citizen. One of them is “naturalisation.”. Naturalisation is for those adults who have acquired indefinite leave to remain in the UK for at least 1 year, or in the case of those on a UK spouse visa where the applicant is married to or in a civil partnership with a British citizen, can apply for British citizenship immediately after acquiring ILR.

Other than having ILR, you need to meet other eligibility criteria to be able to apply for UK citizenship by naturalization. Let us see those criteria:

• Age Requirement - You must be 18 years old or over at the date of application.
• Sound Mind Requirement - You should be of sound mind so that you understand the implications of your decision to naturalize. However, the Home Office may use its discretion while assessing your application to overlook this requirement if it is in your best interest. If you are applying for naturalisation on behalf of somebody who is not of sound mind and you take responsibility for that person, you can provide details of that person’s medical condition and your role as their caregiver at the time of application.
• Residency Requirement - You must have lived in the UK for at least 5 years before you apply, but if you are married to or in a civil partnership with a British Citizen, the minimum residency requirement is 3 years.
• Physical Presence in the UK Requirement - You must have been physically present in the UK, the Isle of Man, or the Channel Islands exactly on the day 5 years before the application is received by the Home Office. If you are married to or in a civil partnership with a British citizen, the same requirement of being physically present in the UK, the Isle of Man, or the Channel Islands is 3 years before the application is received by the Home Office.
• Respecting UK Immigration Law Requirement - You must not have breached the UK immigration laws in the last 5-year or 3-year residence period in the UK before applying for naturalisation. You will meet this requirement automatically if you have been granted indefinite leave to enter or remain in the UK.
• Immigration Status Requirement - You must have acquired settled status, such as ILR or ‘settled’ status under the EUSS scheme, and hold it for at least 12 months on the date of application.

Those married to or in a civil partnership with a British citizen can apply for naturalization immediately after acquiring ILR or settled status.

• Absence Requirement - You must not have spent more than 450 days outside the UK in the 5 years and 270 days outside the UK in 3 years (if you are a spouse or civil partner of a British citizen) before you apply. You also must not have spent more than 90 days outside the UK in the 12 months before you apply. This condition applies to all applicants.
• Future Residence Requirement - All applicants for UK citizenship by naturalization must have intention to continue to live in the UK.
• Life in the UK Test Requirement - All applicants must pass the ‘Life in the UK’ test. When you pass the test, you are given a certificate with a reference number, which you need to provide while completing the naturalization application form. You do not normally need to send the certificate to the Home Office.
• English Language Requirement – Unless exempt, all applicants must also prove their sufficient speaking and listening knowledge of English, Welsh or Scottish Gaelic. You can prove this if you have a qualification in English at B1 CEFR or higher, from the SELT (Secure English Language Test) list.
• Good Character Requirement - This is a statutory requirement as per the British Nationality Act 1981 that those applying to seek to naturalize as British must be of good character. This means you must observe UK laws and show respect for the rights and freedoms of its citizens. You must not have entered the UK illegally.

Application Process

If you are applying from inside the UK, you can apply online or by post. If you are applying from the Channel Islands, the Isle of Man, or a British Overseas Territory, you have to apply by post or in person.

Applying by yourself

You can fill out the application form online. Then, you must submit the required documents as part of the application for UK citizenship by naturalisation. As part of the online application, you will be required to make an appointment at a TLS Contact. You can also apply by post; however, you will still need to book an appointment at TLS contact.

Applying through a representative

You can also apply for British citizenship through a representative. A representative can be a private company or an individual, and they should be registered with the Immigration Advice Authority.
You can also apply through a solicitor or barrister who is not registered with the Immigration Advice Authority. However, they must be registered with one of the approved organizations, such as the Law Society of England and Wales, Faculty of Advocates, and Law Society of Scotland.

After you have applied

Once you have applied and proved your identity, you should usually get a decision on your application generally within 6 months. During this period, you will not lose your existing immigration rights. You can also travel outside the UK during the processing time of your application.

If the UK citizenship application is approved

If the Home Office approves your application for UK citizenship, you will be informed through an email and letter.

Citizenship Ceremony

After acquiring UK citizenship through naturalisation, you must arrange and attend the British Citizenship Ceremony at your local council (in most cases). During the ceremony, you must take an oath of allegiance or affirmation and pledge to respect the rights, freedoms, and laws of the UK.
At the end of the ceremony, you will receive your certificate of British citizenship and a welcome pack.

What if your application is rejected?

If your application to naturalise is refused, you will receive an email and a letter from the Home Office explaining the reasons for refusal. You can choose to request the Home Office to reconsider their decision using the form NR, or else you can apply again for UK citizenship, addressing the issues that caused the refusal in the first place. However, your current right to reside in the UK will not be affected as a result of the citizenship application refusal.

Conclusion

UK citizenship is a complex process and expensive. You should get an expert’s advice before you apply. Once your application is successful, UK citizenship through naturalization offers various advantages. You can apply for a British passport, which allows you to travel to more than 100 countries visa-free or with a visa-at-arrival option.
You also get the right to vote in the UK’s elections at all levels. You can also stand for an election for public office.