Jobs

in general will a firm take you on for part time employment if you have your N.I number but have no reached 16 yet ?

Yes, however you can't earn more than £5,000 per annum. Unless you're talking about a paper route or waiting (even this would be iffy) I doubt very much you'll find anyone who would hire you.

i will not be earning over 5k because ill be working parttime and still be in school ill be working a maximum 15-20 hours per week