How do I find my National Insurance number?

Your National Insurance number never changes — not when you marry, not when you move, not when you change jobs. There is no card any more; the number is confirmed by letter. The fastest route by a wide margin is the HMRC app, which shows it on screen and produces a downloadable letter for anyone who needs to see it.

Step by step

1. Look at the documents you already have.A payslip, a P60, a P45, a letter about tax or tax credits, a pension statement, or a letter about benefits. The number is two letters, six digits and a final letter.
2. Use the HMRC app.Download it, sign in or set up an account, and the number is displayed. You can also download a confirmation letter from within the app, which is what an employer or a bank will accept.
3. Or use your personal tax account.The same information through a browser. Setting up the account takes a few minutes and needs identity verification, and it is useful for a great deal else.
4. Save it where you will find it.The app lets you save the number to a phone wallet. That is far better than a photograph of a payslip in a camera roll.
5. Do not expect HMRC to read it out.HMRC will not give a National Insurance number over the phone or by webchat. This is a security measure and no amount of asking changes it.
6. Use the guided tool if you are stuck.GOV.UK has a short guided route that works out how you can get your number based on your circumstances, including where you cannot get online.
7. Use form CA5403 as the offline route.Complete it online, print and sign it, enclose identity documents, and post it to HMRC. A letter is sent to your registered address, so make sure HMRC has the right one.
8. Do not use commercial lookalike sites.Several sites charge a fee to submit the same free application. Navigate to GOV.UK directly rather than through a search advertisement.
9. Know what it is not.A National Insurance number is not proof of identity and not proof of the right to work. It appears in identity processes only as a supporting element alongside a primary document.

Tips

• Save the number to your phone wallet through the HMRC app. It is the fastest fix for a problem that recurs every few years.
• Download the confirmation letter as a PDF and keep it with your other documents. Employers accept it.
• Check HMRC has your current address before requesting anything by post.

Common mistakes

• Ringing HMRC expecting to be told the number — They will not give it out by phone or webchat. The app, the personal tax account and the postal form are the only routes.
• Treating it as proof of identity — It is not, and organisations that ask for it as identity evidence are asking for the wrong thing. It supports an identity check; it does not make one.

If it doesn't work

Questions people ask