If you start work (FT/PT) or set up as self-employed you must apply for a National Insurance number. If you have the right to work in the UK, you will need to telephone Jobcentre Plus on Tel 0845 600 0643 to arrange to get one. Lines are open 8.00 am to 6.00 pm Monday to Friday and are normally less busy before 9.00 am. They may require you to attend an ‘Evidence of identity’ interview .
You must apply for a National Insurance number to start work but you don’t need to have a plastic National Insurance number card.
If you are an International Student at the University ,apply for National Insurance number ASAP as it is essential for any type of employment.
If you’ve applied for and have been awarded a student loan in UK and you don’t have a National Insurance number, the Student Loans Company will ensure that Jobcentre Plus arrange for you to get one. They may require you to attend an ‘Evidence of identity’ interview .
For more info click on this http://www.hmrc.gov.uk/ni/intro/number.htm