How to Get a National Insurance Number in London
Last updated: November 2026 | Written by [Name] — London Relocation expert.
Moving to London is an exciting new chapter, but between finding a home, setting up a bank account and starting work, it can also feel like a long list of admin. One of the most important steps is getting your National Insurance number, usually called an NI number.
This guide walks you through exactly what an NI number is, who needs one, how to apply, and what to do while you wait. Our goal is to make the process feel clear, manageable and stress-free.
The short answer
Apply online on GOV.UK once you live in the UK and have the right to work. Have your passport, or a national identity card from an EU country, Norway, Liechtenstein or Switzerland, ready. Once your identity has been confirmed, it can take up to four weeks to receive your number—and in most cases you can start work before it arrives.
What is a National Insurance number?
A National Insurance number is a unique reference used by HM Revenue & Customs (HMRC) to record your tax, National Insurance contributions and UK pension history. You will normally need it when you start working, become self-employed or claim certain benefits.
Think of it as part of your essential London paperwork. It does not give you permission to work in the UK, but once you have the right to work, an NI number helps ensure you are taxed and registered correctly.
Do you need to apply for an NI number?
You can apply if you live in the UK, have the right to work in the UK, and are working, looking for work or have a job offer.
Before applying, check whether you already have one. Many people who have previously lived, worked or claimed benefits in the UK already have an NI number—even if they cannot remember it.
Do you need to apply for an NI number?
You can apply if you live in the UK, have the right to work in the UK, and are working, looking for work or have a job offer.
Before applying, check whether you already have one. Many people who have previously lived, worked or claimed benefits in the UK already have an NI number—even if they cannot remember it.
You may need to apply if:
- You are moving to London for work
- You have never worked or claimed benefits in the UK
- You are starting a new job, searching for work, or have a job offer
- You cannot find an existing NI number on official documents
You may already have one if:
- You have lived or worked in the UK before
- You have an older biometric residence permit (BRP) with the number printed on it
- You have an eVisa and can see the number in your UK Visas and Immigration account
Can you start work before your NI number arrives?
Yes—and this is one of the most common concerns for newcomers. In most cases, you can start work before your National Insurance number arrives, provided your employer can confirm your right to work in the UK.
Apply as soon as you can, then pass your NI number to your employer once it arrives. While you wait, your employer can usually handle payroll temporarily, so a delay should not stop you from beginning your new role.
How to apply for a National Insurance number
The application is online, and you need to be in the UK to complete it. The key is to prepare your documents early so the process is as smooth as possible.
Step 1: Check for an existing NI number
Look through payslips, P60s, tax letters, a BRP or your eVisa account. If you find a number, keep it—you do not need to apply again.
Step 2: Gather your documents
You will usually need one of the following:
- A passport from any country
- A national identity card from an EU country, Norway, Liechtenstein or Switzerland
Have your UK address, contact details and immigration information ready too. If you are asked to prove your identity, you may need to upload photos of yourself holding your passport, plus photos of your documents.
Step 3: Apply online
Complete the official application on GOV.UK. You will provide personal details, contact information and identity information.
Once submitted, you will receive an application reference number by email. Save this somewhere safe—it makes any follow-up much easier.
Step 4: Prove your identity
If you can upload clear photos and the requested documents, your application can often be completed online. If you cannot upload photos, you may be asked to attend an appointment or send photocopies instead.
Step 5: Receive your NI number
Once your identity has been confirmed, it can take up to four weeks to receive your National Insurance number, usually by post.
How long does it take?
Once your identity has been confirmed, it can take up to four weeks to receive your NI number.
If more time has passed, you have moved address, or your details have changed, contact the National Insurance number application helpline and have your reference number ready.
Tips for a smooth application
- Apply as soon as you arrive in the UK, rather than waiting for your first payday
- Use clear, well-lit photos if you need to prove your identity
- Keep your application reference number safe
- Check existing documents before applying for a new number
- Remember that an NI number is not the same as a visa or right to work
Insider note from our team
[Expert tip from the London Relocation team]
Frequently asked questions about National Insurance numbers (FAQ)
How long does it take to get a National Insurance number?
Once your identity has been confirmed, it can take up to four weeks to receive your National Insurance number, usually by post.
Can I start work without a National Insurance number?
Yes, in most cases. You can start work before your number arrives, provided your employer can confirm your right to work in the UK. Pass your NI number to your employer once you receive it.
Do I need to be in the UK to apply?
Yes. The application is online, but you need to live in the UK and have the right to work here to apply.
How can I find out if I already have a National Insurance number?
Check payslips, P60s, tax letters, an older biometric residence permit (BRP) or your eVisa account. Many people who have lived, worked or claimed benefits in the UK before already have one.
Does a National Insurance number give me the right to work in the UK?
No. An NI number records your tax, National Insurance contributions and pension history. Your right to work comes from your visa or immigration status.
Settling into London with confidence
Getting your National Insurance number is one of those small but important steps that makes London feel like home. Once it is done, you can focus on the more enjoyable parts of your move—exploring neighbourhoods, building your new routine and settling into life in the capital.
At London Relocation, we help newcomers navigate the practical side of moving to London, so the transition feels less overwhelming and more exciting.
Moving to London?
Contact our team today for personalised support with your relocation.
Sources
This guide draws on official guidance from GOV.UK. Rules and processing times can change, so always check GOV.UK for the latest information.