Misplaced your National Insurance number? Do not worry! From checking payslips to using the HMRC app, there are many ways to recover it. If all else fails, you can request it via post. Here is everything you need to know to locate or apply for your NI number.

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 old plastic National Insurance cards that some of our readers may remember 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.

CIGMA Accounting

CIGMA Accounting Ltd is a forward-thinking accounting and tax firm based in London, dedicated to delivering high-quality compliance, tax planning, and business advisory services to entrepreneurs, landlords, and growing SMEs. With offices in Wimbledon and Farringdon, we combine local expertise with a tech-driven approach to simplify accounting. Our services include corporation tax filing, VAT compliance, HMRC investigation support, R&D tax credit claims, capital allowances optimisation, and bookkeeping automation. What sets CIGMA apart is our ability to blend traditional accounting rigour with AI-powered systems that reduce errors, save time, and provide real-time financial insights. Our team ensures that every client - from startups to high-net-worth individuals - receives a bespoke solution aligned with their growth goals. Whether you need strategic tax planning, help with HMRC disclosures, or a full outsourced finance function, CIGMA Accounting delivers clarity, compliance, and confidence.

See Full Bio

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.

CIGMA Accounting

CIGMA Accounting Ltd is a forward-thinking accounting and tax firm based in London, dedicated to delivering high-quality compliance, tax planning, and business advisory services to entrepreneurs, landlords, and growing SMEs. With offices in Wimbledon and Farringdon, we combine local expertise with a tech-driven approach to simplify accounting. Our services include corporation tax filing, VAT compliance, HMRC investigation support, R&D tax credit claims, capital allowances optimisation, and bookkeeping automation. What sets CIGMA apart is our ability to blend traditional accounting rigour with AI-powered systems that reduce errors, save time, and provide real-time financial insights. Our team ensures that every client - from startups to high-net-worth individuals - receives a bespoke solution aligned with their growth goals. Whether you need strategic tax planning, help with HMRC disclosures, or a full outsourced finance function, CIGMA Accounting delivers clarity, compliance, and confidence.

See Full Bio