By Eternity Accountants Editorial Team · Reviewed by Shamayun Chowdhury, Senior Accountant · Published: 7 November 2026 · Last reviewed: November 2026 · Applies to the 2026/27 tax year
How to find my National Insurance number? The fastest way is the HMRC app or your HMRC personal tax account, where you can view it and download a confirmation letter in minutes. It is also printed on your payslips, P60 and HMRC or DWP letters. HMRC will not give it out over the phone.
Your National Insurance number follows you for life, yet it is easy to misplace. You might need it for a new job, a student loan, a benefits claim, a Self Assessment return or a mortgage application, and usually at short notice.
If you have typed “how to find my National Insurance number” into Google, the good news is that you rarely need to wait. This guide sets out every official way to find your number, from the HMRC app to a postal request, explains what the number looks like, and tells you what to do if you have never had one.
- The HMRC app and your personal tax account show your number straight away and let you download a letter.
- Payslips, your P60 and letters about tax, pensions or benefits all show it too.
- HMRC cannot tell you your number over the phone or webchat; by post it can take up to 10 working days.
- If none of that works, form CA5403 asks HMRC to post the number to you.
- Your number never changes, even if you move abroad, marry or change your name.
- How to find my National Insurance number: the quickest ways
- How to find my National Insurance number online
- Documents that show your number
- How to find my National Insurance number by post
- Can HMRC give it to you over the phone?
- What a National Insurance number looks like
- If you have never had a number
- Common situations
- Keeping your number safe
- Frequently asked questions
- Final verdict
How to Find My National Insurance Number: The Quickest Ways
According to GOV.UK’s guide to finding your National Insurance number, most people can find it in minutes without contacting anyone. The table compares every official route, starting with the fastest.
| Method | What you need | How fast |
|---|---|---|
| HMRC app | A smartphone and a GOV.UK sign-in | Instant |
| Personal tax account | A GOV.UK sign-in | Instant |
| Apple or Google Wallet | Your number saved there earlier | Instant |
| Payslip or P60 | A recent payslip or end-of-year P60 | Instant |
| HMRC, DWP or pension letters | Any letter about tax, benefits or pensions | Instant |
| Form CA5403 by post | Proof of identity and a printer | Up to about 10 working days |
A quick example
Aisha starts a new job on Monday and cannot find her number. On Sunday evening she opens the HMRC app, signs in, downloads her National Insurance letter as a PDF and emails it to HR. The whole thing takes under five minutes.
Which method should you try first?
If you have a smartphone, start with the HMRC app. If you prefer a computer, sign in to your personal tax account. If neither works, check your paperwork before turning to the postal form, because a single old payslip is enough.
Does the number ever change?
No. GOV.UK confirms that your National Insurance number stays the same for life. If you find it on a document from ten years ago, it is still your number today, even if your name, address or nationality has changed since.
How to Find My National Insurance Number Online
The online routes are the quickest, and both let you download an official letter that confirms your number to an employer, university or lender.
How to find my National Insurance number in the HMRC app
- Download the free HMRC app from the App Store or Google Play.
- Sign in with your GOV.UK One Login or Government Gateway details, and prove your identity if asked.
- Open the National Insurance section to see your number.
- Choose to save a letter as a PDF, or add the number to your Apple or Google Wallet.
The app is designed for people who live in the UK. Once your number is in your phone’s wallet, you can show it without opening the app at all.
Using your personal tax account
Your HMRC personal tax account shows the same information on a computer or tablet. After signing in, go to the National Insurance section to view your number and print or download a confirmation letter. The account also shows your tax code, your National Insurance record and any gaps in your contributions.
The GOV.UK checker tool
If you are not sure which route suits you, GOV.UK has a short checker that asks a few questions and tells you where to look or how to ask for your number. It times out after 15 minutes of inactivity and does not save your answers.
Documents That Show Your National Insurance Number
How to find my National Insurance number without going online? The number is probably already in your files. Look for it on:
- Payslips: usually printed near the top, next to your tax code.
- P60: the end-of-year summary your employer gives you each spring.
- P45: the form you receive when you leave a job.
- Letters about tax, pensions or benefits: from HMRC, DWP or a pension provider.
- Your BRP or eVisa: if you came to the UK on a visa, you may already have a number. Check the back of your BRP or your UKVI account.
- Your original letter: the one sent shortly before your 16th birthday.
Self-employed? Your Self Assessment calculations and Class 2 or Class 4 National Insurance letters also carry the number.
How to Find My National Insurance Number by Post
If you cannot use the app or personal tax account and you have no documents, HMRC can post your number to you. GOV.UK’s guidance on getting your number by post sets out the steps:
- Fill in form CA5403 using HMRC’s online form service.
- Print the completed form and sign the declaration.
- Include documents that confirm your identity.
- Post it to: National Insurance contributions and Employers Office, HM Revenue and Customs, BX9 1AN.
HMRC checks your identity, updates your details and posts the number to the address it holds. HMRC says postal confirmation can take up to 10 working days, so if you need it for a new job next week, the app is a far better bet.
Can HMRC Give You Your National Insurance Number Over the Phone?
No. HMRC states clearly that it cannot give you your National Insurance number over the phone or on webchat. This protects you from identity fraud, because anyone could ring and claim to be you.
The National Insurance contact number is 0300 200 3500, open Monday to Friday from 8am to 6pm, or +44 191 203 7010 from abroad. Advisers on this National Insurance helpline cannot read your number out, but they can arrange for your number to be posted to you, and help with gaps in your record, credits and contributions.
What a National Insurance Number Looks Like
Knowing the format helps you spot your number quickly on a document. HMRC’s National Insurance Manual (NIM39110) explains that every number has:
- Two letters at the start
- Six digits in the middle
- One final letter, which is always A, B, C or D
HMRC’s own example is QQ 12 34 56 A, which is not a real number. Some letter pairs, such as BG, GB, NK and ZZ, are never used at the start. A number in the format 11 A1 11 11 is a temporary reference number, not a National Insurance number, and you will still need to apply for a proper one.
If You Have Never Had a National Insurance Number
Most people who grow up in the UK are sent a number automatically in the three months before their 16th birthday, as long as a parent or guardian claimed Child Benefit for them. If you are aged 16 to 19 and never received it, check the methods above first.
How to find my National Insurance number at 16
Your first letter is sent to the address HMRC holds for your family. If it has been lost, ask a parent whether it was filed away. If you have started a part-time job, your payslip will show the number. Once you can prove your identity, the HMRC app works too.
Applying after moving to the UK
If you moved to the UK and have the right to work, you can apply for a National Insurance number online while you are in the UK. It can take up to four weeks, but you can start work before it arrives if you can prove your right to work.
Common Situations and What to Do
The best answer to how to find my National Insurance number depends on your situation. Use this table to pick the quickest route.
| Situation | What to do |
|---|---|
| Starting a new job tomorrow | Use the HMRC app or personal tax account and download the letter for your employer |
| Moved to the UK on a visa | Check the back of your BRP or your eVisa; apply online if there is no number |
| Student applying for a loan or part-time work | Check the HMRC app, your 16th birthday letter or a payslip from a previous job |
| Changed your name after marriage | Your number stays the same; tell HMRC about your new name |
| Living abroad | Use the personal tax account, or call +44 191 203 7010 |
| No smartphone, no online account, no documents | Send form CA5403 by post |
If you are self-employed and need your number for a Self Assessment return, the same methods apply. Your Unique Taxpayer Reference (UTR) is a different number, so do not confuse the two.
Keeping Your National Insurance Number Safe
Your NI number is valuable to fraudsters because it links to your tax and benefits record. Only share it with your employer, HMRC, DWP, your pension provider, student finance, your bank or a regulated adviser who needs it.
- Never post a photo of a payslip or P60 online.
- Be wary of calls, texts or emails asking for your number to “release a tax refund”. HMRC does not ask for personal details that way.
- Shred old payslips and letters you no longer need.
If you think someone is using your number, contact HMRC straight away and check your personal tax account for jobs or income you do not recognise. If your tax affairs need sorting out, our personal tax planning service can help.
Frequently Asked Questions
How can I find my National Insurance number online?
Sign in to the HMRC app or your HMRC personal tax account using your GOV.UK sign-in details. Your number appears in the National Insurance section, and you can download a letter confirming it or add it to your Apple or Google Wallet.
Can I get my National Insurance number over the phone?
No. HMRC cannot give out National Insurance numbers by phone or webchat. The helpline on 0300 200 3500 can arrange for it to be posted to you, which can take up to 10 working days.
Where is my National Insurance number on my payslip?
It is usually printed near the top of the payslip, often next to your tax code or employee number. It is made up of two letters, six digits and a final letter from A to D.
Do I need a National Insurance number to start work?
You need one, but you can start work before it arrives if you can prove your right to work in the UK. Apply online as soon as possible and give the number to your employer when you get it.
How to find my National Insurance number without a smartphone?
Sign in to your personal tax account on a computer, or check a payslip, P60 or HMRC letter. If none of those work, send form CA5403 by post or call the helpline on 0300 200 3500 and ask for the number to be posted to you.
How to find my National Insurance number if I live abroad?
Use your HMRC personal tax account, or check an old payslip or P60 from UK work. You can also call HMRC on +44 191 203 7010 and ask for the number to be posted to the address it holds for you.
Do I still get a National Insurance card?
No. Plastic National Insurance cards are no longer issued. Your number is confirmed by letter, and you can download a fresh letter at any time from the HMRC app or your personal tax account.
Is my National Insurance number the same as my UTR?
No. Your National Insurance number tracks your contributions and benefits for life. Your Unique Taxpayer Reference is a 10-digit number HMRC gives you when you register for Self Assessment.
Final Verdict: How to Find My National Insurance Number in Minutes
So, how to find my National Insurance number fast? Open the HMRC app or your personal tax account and download the letter. If you are offline, check a payslip, P60 or HMRC letter. Only use the postal form when everything else fails, and never share your number with anyone who contacts you out of the blue.
- Download the HMRC app and save your number to your phone’s wallet.
- Check your National Insurance record for gaps while you are signed in.
- See our fixed-fee pricing, or call 0116 4030595 or email info@eternityaccountants.co.uk if you need help with HMRC.
✓ National Insurance record and gaps checked
✓ We deal with HMRC for you
Why trust this guide
- Written by the Eternity Accountants Editorial Team and reviewed by a chartered management accountant (ACMA, MAAT) with more than 15 years’ UK practice experience.
- Every method checked against GOV.UK and HMRC’s National Insurance Manual.
- Helpline numbers and opening hours checked in November 2026.
- Last reviewed: November 2026.
