What is a National Insurance Number?
Your National Insurance (NI) Number is a unique 9-character code — it looks like AB 12 34 56 C. Think of it as your personal tax and benefits identifier. Employers use it to make sure your National Insurance contributions go to the right account, and HMRC uses it to keep track of your tax history.
You only ever get one NI Number — you keep it for life. Once you have it, you'll use it for your employer, tax returns, and benefits claims.
Who needs a National Insurance Number?
You need an NI Number if you're going to work in the UK, claim any benefits, or pay UK tax. Students who will also be working part-time need one too. If you're not working or claiming, you don't need to apply straight away — but most people apply as soon as they arrive.
What you'll need before you start
Get these ready before you begin your application. Having everything in front of you saves time.
- Your passport or travel document (the one used for your visa)
- Your Biometric Residence Permit (BRP) if you have one
- Your UK address (you'll need this for the application)
- Your date of birth
- Your employment details, if you're already working (employer name and address)
Step-by-step guide
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1
Check you're eligible to apply
You can apply for an NI Number if you have the right to live and work in the UK. This includes people with a valid work visa, student visa with permission to work, BRP, or settled/pre-settled status. If you're not sure, check your visa conditions first.
Check eligibility on GOV.UK -
2
Apply online via GOV.UK
Go to the official GOV.UK NI Number application page. The application takes around 20–30 minutes. You'll be asked about your right to work in the UK, your personal details, and your employment situation.
Go to GOV.UK applicationImportant: Only apply via the official GOV.UK website. Be careful of unofficial sites that charge a fee — applying is free.
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3
Prove your identity (if asked)
After submitting your online application, you may be asked to prove your identity. This usually means uploading a photo of your passport or BRP through the GOV.UK identity verification process. You'll get instructions by email.
Not everyone is asked to do this — if you're not, you'll simply receive your number by post.
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4
Wait for a decision (usually 2–4 weeks)
Once you've submitted your application and verified your identity, your NI Number will be sent to you by post. The letter will contain your number and a reminder to keep it safe. Processing usually takes 2–4 weeks, though it can take longer during busy periods.
You don't need to wait for your NI Number to start work. You can give your employer your application reference number in the meantime.
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5
Tell your employer your NI Number
Once your letter arrives, tell your employer your NI Number as soon as possible. They'll use it to make sure your tax and National Insurance contributions are properly recorded. Double-check the letter carefully — the number is yours for life.
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6
Keep your NI Number safe
Your NI Number is sensitive personal information. Store the letter in a safe place and make a note of the number somewhere secure. You'll be asked for it throughout your working life — for payslips, pensions, and government services.
What to do if you lose your NI Number →
📍 If you live in Northern Ireland: The process is the same, but you may be directed to a local jobs and benefits office for identity verification. Processing times may differ slightly.
What to do next
Once you have your NI Number, these are the most common tasks people tackle next: