If you have lost or forgotten your National Insurance number, there are several ways to retrieve it.
You can find your National Insurance number:
You can also download a letter showing your National Insurance number through your personal tax account or the HMRC app.
If you are still unable to find your National Insurance number, you can request it online, submit a written request to HMRC using form CA5403 or contact HMRC by phone. Teenagers will usually receive a letter with their National Insurance number just before turning 16.
If you have never been issued a National Insurance number, you can apply for one, provided you meet the eligibility criteria.