How to Find and Check Your National Insurance Number

To find your National Insurance number, check a recent payslip, your latest P60, or any letter from HMRC or the DWP — it is printed on all of them. If nothing is to hand, sign in to your Personal Tax Account on GOV.UK or open the HMRC app and you can view it on screen straight away, or ask HMRC to post a confirmation letter.¹

The number is two letters, six digits, and a final letter of A, B, C, or D — for example, QQ 12 34 56 A.² Anything shorter, longer, or ending in another letter is not your number. It stays with you for life and doesn’t change.

Paperwork That Already Has It

Before going online or calling anyone, look through what you already have. Your National Insurance number appears on:

Payslips from any employer.
Your P60, the end-of-year certificate handed out each April.
Letters from HMRC or the DWP — tax coding notices, benefit award letters, State Pension correspondence.
Self Assessment tax returns you’ve filed.
The original notification letter HMRC sent before your 16th birthday, if you kept it.

Any one of these is a reliable record.¹

Check It Online

Personal Tax Account

Your Personal Tax Account on GOV.UK shows your National Insurance number as soon as you sign in. If you don’t already have Government Gateway sign-in details, you can set them up during the same visit. You may be asked to prove your identity with a passport or driving licence.³ Once you’re in, the number is on screen and you can download a confirmation letter as a PDF.

The HMRC App

The HMRC app does the same job from a phone. Download it, sign in with your GOV.UK credentials, and your number is visible in the app. You can save it to your phone’s digital wallet, and after the first sign-in you can get back in with a PIN, fingerprint, or facial recognition.⁴

If the online service can’t verify your identity, it will post the number to the address HMRC holds for you. That takes up to 10 working days in the UK, or 21 working days if you live abroad.¹

Get It by Phone or Post

If the online route isn’t working, call the National Insurance enquiries line on 0300 200 3500. HMRC will not read your number out over the phone for security reasons, but the advisor can post a confirmation letter to your address on file. Allow up to 10 working days for it to arrive.⁵ Have your personal details ready so they can find your record.

You can also request the number by post using form CA5403. Complete it online at GOV.UK in one sitting (partial forms can’t be saved), print it, sign the declaration, and send it with identity documents to National Insurance Contributions and Employers Office, HM Revenue and Customs, BX9 1AN.⁶ This is the slowest option. Use it when online and phone aren’t practical.

If You’ve Never Had One

These routes only work if a number was issued to you. Anyone who lived in the UK as a child and had Child Benefit claimed for them was sent one automatically in the three months before turning 16.⁷ If that never happened — most often because you’ve moved to the UK as an adult — you need to apply for one, not find one. The application is on GOV.UK and asks for a passport or an EU, Norwegian, Liechtenstein, or Swiss national identity card, plus a photo of you holding it. Once your identity is confirmed, the number arrives by post within about four weeks.⁸

Watch for Scams

Every official route to your National Insurance number is free. Websites and companies offering to “find” your number for a fee are not connected to HMRC, and the same information is available directly from HMRC at no cost.¹

Because the number stays with you for life, it’s useful to identity fraudsters. Only share it when you genuinely need to — starting a job, dealing with HMRC, claiming benefits. HMRC will not phone, text, or email out of the blue to ask for it. Suspicious contacts can be reported through GOV.UK or by calling 0300 200 3500.⁵

1
GOV.UK. Find Your National Insurance Number
2
GOV.UK. HMRC National Insurance Manual – NIM39110 – What a NINO Looks Like
3
GOV.UK. Personal Tax Account – Sign In or Set Up
4
GOV.UK. Download the HMRC App
5
GOV.UK. National Insurance – Enquiries
6
GOV.UK. Get Your National Insurance Number by Post
7
GOV.UK. Apply for a National Insurance Number
8
GOV.UK. Apply for a National Insurance Number – How to Apply