peter croasdale

My employer, the NHS, has been using an incorrect national insurance number since 2008, they have only just changed it to the correct number so the number on the payslip and latest p60 is now correct. The incorrect number was similar to my correct number, the second letter was wrong. How do I go about correcting my national insurance record from 2008-2023? Should my employer do this? or should it be me. I have most of my payslips and P60's going back over 30 years. thank you for reading