You will need to apply for a National Insurance Number as soon as you arrive. You will need to supply this to the school for tax purposes.
When you arrive in the UK, you will need to call Job Centre Plus on the phone number below:
Telephone: 0345 600 0643
Monday to Friday, 8:30am to 5pm
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:
marriage/civil partnership certificate