From ILR to Citizenship: Your Complete Guide to British Naturalisation in 2025

If you’ve already got indefinite leave to remain (ILR) in the UK, you’re probably thinking about what comes next. For many people, that next step is becoming a British citizen through a process called naturalisation. It’s a big decision that comes with real benefits, from unrestricted travel with a British passport to the right to vote in UK elections.

But moving from ILR to citizenship isn’t automatic. You’ll need to meet specific requirements, gather the right documents, and understand exactly what the Home Office expects from your application. In this guide, we’ll walk you through everything you need to know about making that transition in 2025.

Understanding the Difference Between ILR and British Citizenship

Before you start your citizenship application, it’s worth understanding what actually changes when you go from ILR to full British citizenship.

What ILR Actually Gives You

Indefinite leave to remain lets you live and work in the UK without time limits. You won’t need to renew a visa every few years, and you’re not tied to a specific employer or sponsor. It’s often called “settled status” because it feels permanent.

But there’s a catch. If you leave the UK for more than two years continuously, you’ll lose your ILR status. You also can’t vote in general elections, and you don’t automatically have the right to pass British nationality on to children born outside the UK.

What Changes with Citizenship

British citizenship is permanent. Once you’re naturalised, you can’t lose it by spending time abroad. You’ll be able to apply for a British passport, which opens up visa-free travel to many countries. You can vote, stand for public office, and work in roles that require UK nationality (like certain civil service positions).

Most importantly, citizenship can’t be taken away just because you’ve been living elsewhere. It’s yours for life.

Should You Keep Your Original Nationality?

The UK allows dual citizenship, so you won’t be forced to give up your current passport. However, not every country permits dual nationality. Some nations require you to renounce your original citizenship when you become British. Check with your country’s embassy before applying to avoid any surprises.

When Can You Apply for Citizenship After Getting ILR?

Timing matters when you’re planning your path from ILR to citizenship. The waiting period depends on your personal circumstances.

The Standard 12 Month Wait

Most people need to hold ILR for at least 12 months before they can apply for British citizenship. This gives you time to settle into permanent residency and demonstrate that you’re committed to living in the UK long-term.

During this year, you should keep track of your travel. If you spend too much time abroad, it could affect your citizenship application later.

Immediate Application for Spouses

If you’re married to or in a civil partnership with a British citizen, you can skip the 12-month waiting period. As soon as you receive ILR, you’re eligible to apply for citizenship straight away through the spouse visa route.

You’ll still need to meet all the other requirements, but you won’t have to wait that extra year.

2025 Immigration White Paper Changes

There’s something important you should know about proposed changes. The UK government’s 2025 Immigration White Paper suggests extending the route to ILR from five years to ten years for most migrants. If these proposals go ahead, people would need to wait 11 years before becoming eligible for citizenship (10 years to ILR, plus 12 months).

The White Paper also mentions an “earned settlement” system, where applicants would need to show contributions like working in priority sectors or community involvement. These aren’t law yet, and it’s unclear whether they’ll apply to people already on the five-year route.

If you’re eligible now, it might be worth applying under the current rules while they’re still in place.

British Citizenship Eligibility Requirements

Naturalisation isn’t guaranteed, even if you’ve held ILR for the required time. UK Visas & Immigration (UKVI) will assess whether you meet several conditions.

Age and Capacity

You must be at least 18 years old and of sound mind (what the law calls “full capacity”). If you’re applying for a child, there’s a separate process with different requirements and a lower application fee of £1,214.

Residency Requirements Explained

This is where many applications run into trouble. You need to prove you were physically in the UK on a specific date five years before your application is received by the Home Office. For spouse or civil partner applications, it’s three years.

You also can’t have spent more than 450 days outside the UK during the five-year period (or 270 days for the three-year period). On top of that, you can’t have been absent for more than 90 days in the final 12 months before applying.

Example: Sarah has lived in the UK for five years and visited family abroad for a total of 380 days. She’s within the 450 day limit, but if she spent 95 days abroad in the last year, she’d exceed the 90 day limit and might face issues.

Throughout this period, you must have held valid immigration permission. Any time spent in the UK illegally or without proper leave won’t count.

Good Character Requirement

The Home Office expects applicants to have shown respect for UK laws and fulfilled their responsibilities as residents. This isn’t just about avoiding serious crimes. They’ll look at:

• Criminal convictions (even spent ones may be considered)
• Immigration breaches in your history
• Financial conduct, including tax obligations and bankruptcy
• Honesty in previous applications

The 2025 guidance specifically states that people who entered the UK illegally will “normally” be refused citizenship, regardless of how long ago it happened. This includes those who arrived via small boats or hidden in vehicles.

If you have any past issues, being upfront about them and providing context can help. The Home Office considers each application individually.

Knowledge of Language and Life in the UK

You need to prove you can speak English and know about life in the UK. Most people satisfy this by:

• Passing the Life in the UK test (you probably already did this for ILR)
• Showing English language ability at B1 level or above

If you used a B1 qualification for your ILR application, you don’t need to retake it for citizenship. The test results are valid for two years.

You’re exempt from language requirements if you’re 65 or older, or if you have a long-term physical or mental condition that prevents you from meeting them. You’ll need medical evidence to support an exemption claim.

Nationals from majority English-speaking countries don’t need separate language qualifications, but they still must pass the Life in the UK test.

The ILR to UK Citizenship Application Process

Once you’re confident you meet all requirements, it’s time to apply. The process involves several steps and costs £1,735 for adults (including the £130 citizenship ceremony fee).

Documents You’ll Need

Gather these before you start:

• Your current passport
• Your biometric residence permit (if you have one)
• Marriage or civil partnership certificate (if applying as a spouse)
• Proof of all addresses during your qualifying period
• Life in the UK test pass certificate
• English language qualification
• Two referees who can confirm your identity

Your referees need to be over 25, have known you for at least three years, and meet certain professional criteria. At least one should hold a British passport.

Submitting Your Application

You can apply online or using Form AN. Most people find the online route simpler. You’ll need to:

• Complete the application form
• Pay the £1,735 fee (non-refundable, even if refused)

For biometrics, you’ll either use the UK Immigration: ID Check app on your smartphone or attend a UK Visa and Citizenship Application Services (UKVCAS) appointment. You can also scan documents at your UKVCAS appointment or upload them online.

Processing Times

UKVI aims to decide most applications within six months. Some take longer, especially if they need additional information or checks.

You can’t chase your application until six months have passed. If the Home Office needs more documents, they’ll contact you directly.

After Your Application is Approved

Getting approval is brilliant news, but there are still a few steps to complete.

Attending Your Citizenship Ceremony

You’ll receive an invitation telling you which local authority to contact. You must book your ceremony within three months of getting the invitation.

At the ceremony, you’ll take an oath of allegiance and pledge loyalty to the UK. It’s a formal occasion where you promise to respect British laws and values. Afterwards, you’ll receive your certificate of naturalisation.

Returning Your Biometric Residence Permit

This is crucial: within five working days of receiving your citizenship certificate, you must send your biometric residence permit back to the Home Office. If you don’t, you could be fined up to £1,000.

The certificate of British citizenship is now your proof of status. Keep it somewhere safe.

Applying for Your British Passport

Once you have your naturalisation certificate, you can apply for a British passport. You’ll need:

• Your certificate of British citizenship
• The passport you used to come to the UK
• A digital photo
• Payment for the passport fee

You can apply online or by post. Standard processing takes about three weeks, though faster services are available for an additional fee.

Common Reasons for Citizenship Application Refusals

Understanding why applications fail can help you avoid the same mistakes. The most common issues include:

Insufficient Documentation

This is the biggest reason for refusals. Missing documents, unclear photocopies, or failing to respond fully to Home Office requests can all lead to rejection. Make sure everything is complete before submitting.

Residence Requirement Failures

Miscalculating your absences from the UK is surprisingly common. Even being one day over the 90 day limit in your final year can cause problems. Keep detailed records of every trip abroad, including exact dates.

Good Character Concerns

Undeclared criminal convictions, even minor ones, can lead to refusal. So can evidence of dishonesty in previous immigration applications or financial problems like unpaid taxes.

The Home Office does extensive background checks. If there’s anything that might be flagged, it’s better to address it upfront with supporting context.

Immigration Breaches

If you previously overstayed a visa, worked without permission, or had any other immigration problems, these can affect your application. The Home Office may exercise discretion if you can show compelling reasons, but there’s no guarantee.

Getting Professional Help with Your Application

Given that citizenship fees are non-refundable and applications can be complex, many people choose to work with immigration solicitors in Manchester who understand the naturalisation process inside out.

A solicitor can:

• Review your residency calculations to ensure you meet requirements
• Check all documents before submission
• Identify potential issues with your good character assessment
• Prepare supporting statements if needed
• Handle communication with the Home Office

This is particularly valuable if you have any complications in your immigration history or you’re uncertain about meeting the requirements.

Ready to Take the Next Step?

Moving from ILR to citizenship is a significant milestone that requires careful preparation and accurate documentation. Whether you’re just starting to think about naturalisation or you’re ready to apply, getting the details right is essential.

If you’re concerned about meeting the requirements or want to make sure your application is as strong as possible, speaking with an immigration specialist can give you confidence and clarity. Our team has helped countless clients in Manchester successfully complete their journey to British citizenship.

Call us on 0161 464 4140 or book a consultation online to discuss your specific situation. We’ll review your eligibility, answer your questions, and guide you through every step of the application process.