National Insurance Guide -- Updated July 2026
National Insurance Number Guide 2026/27
Your National Insurance number is the personal reference HMRC and the Department for Work and Pensions use to track your National Insurance contributions, tax records and entitlement to state benefits and the State Pension throughout your working life. This guide explains who needs one, how to apply if you do not already have one, what the format means, and what to do if you cannot find yours.
What a National Insurance Number Is For
A National Insurance (NI) number is a unique personal identifier used to record the National Insurance contributions you and your employer pay, and to link those contributions to your entitlement to the State Pension and contributory benefits such as New Style Jobseeker's Allowance and New Style Employment and Support Allowance. It also allows HMRC to match your tax records correctly across employments.
Most UK residents are automatically issued an NI number shortly before their 16th birthday if their parent or guardian receives Child Benefit for them. Others -- including many people moving to the UK to work -- need to apply.
Who Needs to Apply
You need to apply for an NI number if you are living in the UK and plan to work, claim benefits, or apply for a student loan, and you do not already have one -- typically because you have moved to the UK from abroad and were not automatically allocated one as a teenager.
You do not need an NI number simply to start working -- you can start a job before your number arrives, as explained below -- but you will need one to be correctly taxed long-term and to build up a qualifying record for the State Pension.
How to Apply
Applications are made online through gov.uk. You will typically need to prove your identity (such as a passport or biometric residence permit) and confirm your right to work or study in the UK. In some cases you may be asked to attend an appointment or provide further evidence before a number is issued.
Processing can take several weeks, particularly during busy periods, so it is worth applying as soon as you know you will be living and working in the UK rather than waiting until you start a job.
What the Format Means
An NI number follows the pattern two letters, six digits, one letter (for example, QQ 12 34 56 C). The final letter is always A, B, C or D and has no special meaning beyond completing the format; the first two letters exclude certain combinations reserved by HMRC and are never allocated to individuals in a way that reveals personal information.
Your NI number does not change over your lifetime, even if you change your name, move address, or leave and return to the UK -- you keep the same number for life.
Starting Work Without a Number
You do not have to wait for your NI number to start a job. Tell your employer you have applied (or are applying) and give them proof, such as an application receipt reference, and they can begin paying you, usually placing you on an emergency tax code initially and correcting this once your number and full tax details are confirmed.
Once you receive your number, give it to your employer promptly so it can be added to your payroll record and your contributions correctly credited.