yes i'm sure you don't need a NI number to start work, you need to apply for an NI number as soon as possible thou when you have started, You will need to quote your NI number to your employer's accounts department for taxation purposes.
In order to apply for the number you will need documentation to do with employment (such as a contract or letter from your employer), so it is easier to apply once you have secured employment. If you have not yet secured employment, you can still apply, however certain documents will be required (such as job rejection letters, letters from your recruitment agent etc).
we were lucky, as me misses need a NI number for tax creds purposes
