P45 incorrect date

My ex employer has put the incorrect date on my p45 in match they said they would change this but before they do I need to confirm that I have destroyed my old p45. Once I confirm they will then amend it . Online it says not to destroy your p45.

Hi
Generally an employer would not produce a replacement p45, however it would deppend on the way they are correcting the issue, ie are they amending your end date on their software and the information they've sent to HMRC.
I would suggest getting your employer to contact HMRC directly to discuss this.
Thankyou.