Question: how to get your national insurance number when you've lost it?
Answer: If you lose or forget your National Insurance number (NINO), you may be able to find it on official documents – for example, payslips from a job, your tax return, or a PAYE coding notice. It is also possible to ask HMRC to confirm it by: completing form CA5403 'Your National Insurance Number' and sending it to HMRC; or.