Your National Insurance (NI) number: What is it and why is it so important?

You may have noticed that recently, some of our regular authors at CBW have started writing more and more content for those embarking on the working world.

Take a listen to our latest podcast from our CBW Financial Planning team, which puts some of CBW’s recent graduates in the spotlight to see what they know about things like savings and pensions. When we all start our first jobs, we’re expected to know and understand things like what the details of our payslip mean, but where and at what point are we supposed to learn this? We suspect that many starting work, often post school or university, don’t have all the answers and we therefore want to help fill in some of those gaps. Check out CBW’s Reshma Johar’s latest article on ‘what is a payslip’.

Below, Reshma explains what our national insurance number is for, when we will need it and how to access what you have paid towards NI.

A national insurance number (otherwise known as your NI number) is built up of a series of letters and numbers. It is issued to you just before your turn 16 and will never change.

Just to be clear, the NI number which has been allocated to you, is for your use only.

When you will need your NI number:

  • When you start working
  • Applying for a student loan
  • If you need to claim benefits including tax credits
  • Register for self-assessment tax returns
  • Register as self-employed
  • Registering at the doctor or dentist
  • Opening a bank account

There seems to be two different types of people: the first are the ones that have memorised their NI number and can provide this as and when required. The other, like me, would need to refer back to a document containing their NI number.

If you are like me, and have not remembered your NI number, you can locate this by looking at your:

  • Payslip
  • P60 end of year tax statement provided by your employer
  • P45 if you leave a job
  • Self-assessment tax return
  • Other HMRC document such as a PAYE tax code

And if you still can’t locate your NI number, complete an online form CA5403 and HMRC will confirm it.

What does national insurance pay for?

Any national insurance contribution you make goes towards funding:

  • The NHS
  • State benefits and disability allowances
  • The state pension

In the tax year ended 5 April 2021 the UK government raised a total of £915 billion from various taxes and other sources.  Of the total raised, NI is the second largest receipt of taxes, generating £116 billion.

Finally, you can at any point review your NI record to see how much you have paid in NI and whether there are any gaps or credits. Gaps can be topped up via a voluntary NI contribution payment. This can be made online or requested by post.