A National Insurance (NI) number is a personal number used:

• to record a person's NI contributions and credited contributions
• as a reference number for the whole social security system.

A NI number should only be given to one person and must only be used by that person.

You do not have a legal right to an NI number, but there are circumstances when you are legally obliged to apply for a NI number and register for NI purposes.

Where to to apply for a National Insurance number

You should apply for a National Insurance number through your local Jobcentre Plus office, Jobcentre or social security office. To find your local office go to Find Your Local Office. (This link will take you to the Jobcentre Plus website.)

When you can apply for a NI number

If one of the following applies to you, you can apply for a NI number:

• you want to claim benefit
• you are starting work
• you are self-employed
• you are looking for work
• your partner is claiming benefit for you
• you want to pay voluntary NI contributions and would benefit from paying them.

When anyone applies for a NI number we have to:

• check their identity
• make sure they need a NI number.

We do this to make sure you are who you say you are, to make sure any information we have about you is right, and to protect your NI and social security accounts.

We will check to see if we already have an NI number for you. If we do not find one, we will write and ask you to come to an Evidence of identity interview.

Evidence of identity interview

At the interview we will ask you questions about your background to help us build up a picture of your circumstances. This information and any official documents you bring with you will help to prove your identity. You may also have to complete a form to apply for a NI number.

When we give you the date of the interview, we will tell you what information or evidence to bring with you. The information or evidence you need to bring depends on why you need the NI number. The interview will usually be one-to-one unless for example, you need an interpreter.

There is a list on this web page to give you an idea of the documents you can bring to help prove your identity.

You can get this from your social security office or Jobcentre Plus office.

Sometimes we may ask for your consent to let us keep your documents for a short time. We will give you a receipt for any documents you let us keep.

Types of evidence and information

Here are some examples of the types of evidence and information we need. We cannot accept photocopies.

General documents such as your:

• passport
• National Identity card
• birth certificate
• marriage certificate.

Documents to do with employment, such as:

• payslips
• a work permit
• a letter from your employer
• your contract of employment
• details of any employment agencies you are registered with.

Documents to do with self-employment, such as:

• invoices
• letters from your accountant
• letters from your clients
• your Schedule D tax form.

You must bring any travel documents you have. These are documents that give information about your travel between countries. Travel documents include things like your passport, National Identity card or form NASS 35 that is issued to people seeking asylum in the UK.

If you have any other documents that you think may help prove your identity, please bring them with you.

If you do not have any documents you must still go to the interview.

You may be able to prove your identity with the information you give at the interview.

If your application is successful, we will give you your NI number in writing as soon as possible after the interview. We will send you an NI numbercard later. If your application is successful we will write and tell you.

Remember - a National Insurance number is not proof of identity.

There is more detailed information about National Insurance numbers on the HM Revenue & Customs website.