Salary not showing with HMRC - what now?

TLDR on scenario - HMRC do not have a record of the last salary payment from ex-employer, ex-employer says they have reported it. Appears an unresolvable stalemate. What happen now? Long version: Left employment on 7th July 23. Ex-employer pays last monthly salary 10th July in regular payroll run. Ex-employer provides paper payslip and P45. Records with HMRC show monthly salary April 23 to June 23 inclusive. July 23 payment not showing. Salary with new-employer August 23 is showing. Ex-employer states all submissions have been made and say it must be an HMRC issue. They do not appear willing to discuss further. HMRC state it is an issue the ex-employer needs to resolve. HMRC have acknowledged the employees concerned and updated their tax code to reflect projected earnings to a 1257LX. Employee will have all the info for a 23/24 tax return and the tax code update should mean tax paid is correct too. Main issue is HMRC do not and will not have July 23 salary recorded unless someone resolves the issue. Suggestion has been made that ex-employer calls HMRC to resolve, they don't see it as their issue and therefore will not call HMRC. I would appreciate some information on what happens next?

Hi
If you have received a payslip which shows the information, you can write to us with a copy and advise that you are having issues with the employer not being willing to contact HMRC to resolve the issue.
Income Tax: general enquiries

March 24, and last pay of the tax year is in, and this has still not been resolved. HMRC had copy payslip and P45 from ex-employer months ago, On calling to chase I was told the task was on hold, then on next call it was in the wrong queue. HMRC have changed my tax code twice this year and refunded tax twice , absolutely incorrectly. Now my 24/25 tax free allowance has been reduced, to recover an incorrect amount, and I'd rather settle this now than have it drag on further. Will HMRC accept the figures I provide, which are factual and can be evidenced, or will it never be resolved?

Hello. I have similar issue. Since February when my employer changed accountant I have received the payslip for February wage but can't see this salary in HMRC personal tax account. I have contacted my employer but he is saying that from his side everything was done correctly. However all previous wages is showing on HMRC personal tax account just the one after he changed accountant. Could you please tell me what can I do to this matter as he don't want to take any action. I have all payslips but can see this on HMRC. Thank you for any help

1 hour 21 minutes on the phone to HMRC later they told me they would resolve it based on the evidence. 4 days letter HMRC have sent a letter saying the employer needs to send them the information - HMRC have known for over 7 months that the employer will not engage as claim to have made all required submissions. Quite the shambles.

Hi

If any error exists on your employment record or you have any doubts on any information provided, we would not leave the issue unresolved.
To help us progress your case, we may require specific information - please contact us by webchat or phone via Income Tax: general enquiries

Thank you

Hi Natalia Urban,
If not shown then the employer would need to submit the details online.
If they are not sure how to do this they can contact our Employers helpline Employers: general enquiries.
If they will not take any action then I would submit a letter explaining the situation with your payslips to reivew.
The address is HMRC,
Self Assessment & PAYE,
BX9 1AS
UK
Thank you.