You should not pay any National Insurance, if you earn less than the lower threshold of £105 (2008/09 rates) as shown on the tax rates page »
If you receive more than this amount you will pay National Insurance of up to 11% on anything over this amount.
When you start work, you will be asked to give your employer your National Insurance number. This is way the Inland Revenue identify you and track you through the tax system. You must therefore keep this in a safe place.
Your National Insurance number will contains 2 letters, 6 numbers, 1 letter and will look similar to this AB123456C.
If you do not have a National Insurance number then you need to use a temporary number. This will contain TN (Temporary Number), date of birth (ddmmyy,) M or F (Male or Female), ie male born on 20 August 1968 will be TN200868M.
To obtain a permanent National Insurance number you need to contact your local Jobcentre and they will guide you through the process.