You can check your National Insurance number online in a few minutes at gov.uk/find-national-insurance-number or through the HMRC app. Sign in, prove your identity, and your number appears on screen. You can also download a letter confirming it.
Using the GOV.UK Service
Go to gov.uk/find-national-insurance-number and sign in. You have two sign-in options: a Government Gateway user ID and password, or GOV.UK One Login credentials (an email address and password).1GOV.UK. HMRC Online Services: Sign In or Set Up an Account If you already use HMRC online services, you likely have a Government Gateway account. If you’ve used other government services like Universal Credit, you may already have a GOV.UK One Login.
After signing in, GOV.UK asks you to confirm who you are using a passport or driving licence.2GOV.UK. Find Your National Insurance Number Once verified, your National Insurance number appears on screen.
If you cannot prove your identity online, you won’t be able to view your number this way. HMRC will instead post a letter with your number to the address they have on file.2GOV.UK. Find Your National Insurance Number
Using the HMRC App
The HMRC app does the same job on your phone. If you live in the UK, you can view your National Insurance number inside the app after signing in.2GOV.UK. Find Your National Insurance Number The app also lets you download a letter showing your number, which is the same letter available through your Personal Tax Account on the website.
Downloading a Confirmation Letter
Whether you use the website or the app, you can download a letter that confirms your National Insurance number. It works as proof when you need to share your number with an employer, pension provider, ISA provider, or the Department for Work and Pensions.2GOV.UK. Find Your National Insurance Number The download sits inside your Personal Tax Account once you’ve signed in and verified your identity.
Check Your Existing Paperwork First
Before signing in, it’s worth a quick look through your papers. Your National Insurance number appears on tax-related documents like your payslip or P60.3GOV.UK. Your National Insurance Number A P45 from a previous employer will show it too, and any letter from HMRC about tax or National Insurance usually prints it near the top. Finding it this way saves you the identity check online.
If the Online Service Doesn’t Work
If you can’t get through online and can’t find your number on any paperwork, you have two offline routes.
You can phone HMRC and ask for a confirmation letter. They will not read out your number over the phone or through webchat, but the posted letter typically arrives within 10 working days if you live in the UK, or 21 working days if you live abroad.4GOV.UK. Find Your National Insurance Number – Section: Other Ways to Get Your National Insurance Number
You can also use form CA5403. Fill it in online at GOV.UK, print it, sign the declaration, include documents confirming your identity, and post everything to HMRC at the address on the form.5GOV.UK. Get Your National Insurance Number by Post You cannot save a partly completed form, so have your details ready before you start.4GOV.UK. Find Your National Insurance Number – Section: Other Ways to Get Your National Insurance Number
If You’ve Never Had a National Insurance Number
The steps above only work if you already have a National Insurance number on record. If you’ve never had one, which is common for people who’ve recently moved to the UK, you need to apply rather than check. You can only apply while you’re in the UK, and the application is done online.6GOV.UK. Apply for a National Insurance Number