If you have lost or forgotten your National Insurance number there are a number of ways to locate it. Firstly, you could try and locate the number on paperwork such as your tax return, payslip or P60. You can also use your personal tax account or the HMRC App to find your National Insurance number.

If your National Insurance number still cannot be found a request can be submitted in writing to HMRC using form CA5403 or by telephone. HMRC will not disclose your number over the telephone and will instead send the details by post to the address HMRC has for you on file. The details should arrive within 15 days.

Teenagers should automatically be sent a letter just before their 16th birthday detailing their National Insurance number. These letters should be kept in a safe place. The previously issued plastic National Insurance cards are no longer available.

The National Insurance number helpline can help those aged between 16 and 20 who have not received a letter with details of their National Insurance number as well as other new applicants.

An individual must have the right to work or study in the UK in order to apply for a National Insurance number.