National Insurance Number
If you do not know your National Insurance Number, there are a number of ways in which you can find it out.
From a Payslip
Most payslips from employers will contain your National Insurance Number
In Communications from the DWP
Most letters or communications from the Department of Work and Pensions (DWP) will contain your national insurance number.
On the HMRC Website
HMRC website – https://www.gov.uk/national-insurance/your-national-insurance-number
By Calling the National Helpline
Telephoning helpline on 03002-003500