You can start work before your National Insurance number arrives if you canprove you can work in the UK. You should tell your employer that you’ve applied for one, and give it to them when you have it.
National Insurance number interview
Jobcentre Plus may write to you and ask you to come to an interview where you’ll be asked about your circumstances and why you need a National Insurance number.
The letter will also tell you which documents to bring to prove your identity, eg:
passport or identity card
birth or adoption certificate
marriage or civil partnership certificate
You’ll be told at the interview how long it’ll take to receive your National Insurance number.
If you turned 16 and didn’t get a number
You should be sent a National Insurance number automatically just before your 16th birthday if you live in the UK.
SSAFA help with
Health & Social Work
Adoption & Fostering
Children with Additional Needs
Mental Health First Aid
Service Support Overseas
Offenders & Ex Offenders