Retired end of May. P45 YTD value added to payslip from other previous pension provider

I retired end of May this year and duly notified HMRC by sending details of my P45 to cover my gross earnings in April and May of this year. I have two small pensions from previous employers that I have been receiving over the past year or so. I happened to notice that in July, the paylsip from one of these two pension providers had jumped by a considerable sum that was far greater than the amount actually paid into my bank account by this pension provider. Much correspondence followed between myself and the pension provider culminating in them advising me that when I retired they were instructed by HMRC to add the earnings I had reflected on my P45 to their payslips. I can see now that the differential figure showing on their paylsips between June and July is indeed the amount my last employer paid me in April and May this year and what I disclosed to HMRC upon retiring. My concern is that when coming to submit a self-assessment for myself for FY ending April 2025, I would have declared the 2 months gross income I was paid by my last employer (as per my P45 from them), plus the income from the two modest pensions I have been receiving. However if I do that, the income from my last employer (ex P45) has now been added to one of these two small pensions. Question is it normal practice for HMRC to advise a 3rd party existing pension provider to add a sum (ex P45) from the last emploter to their payslip and if that is the case, then presumably any self assessmnet I filled out would NOT include the two months income I recived from my last employer...otherwise It would be considered twice for tax purposes. Thanks In advance

Hi,
This is standard practice, t allows us to calculate the tax free allowances that we can apply to your pension source after the employment these allowances had previously been allocated to had ended.
When you complete your return, you would include the two months income from your employer, but also include the tax paid on that income. You would also include the pension income received from both of your pension sources, along with the tax paid on these pensions.
If you require any assitance confirming the correct figures to enter,  please contact our Self Assessment team.
Self Assessment: general enquiries
Thank you.

THanks for clarifying thats its normal practice. You also clarified that when I do my tax return for FY ended April 2025, I include the earnings from April & May from my last employer, along with the tax that was deducated at source (PAYE) by that employer. What I dont follow is that , that gross amount (Apr/May 2024 earnings) has been added to one of my pensions, so on the pension payslips from that pension provider, the two months salary appears on my final payslips from my last employer and the P45 they issued AND now appears in the YTD paymnets from this pension provider (not related to my last employer). My concern is when I fill in my tax return for FYE APril 2025 and I put in the following figs P45 from last employer (APril/May 2024); period 12 YTD figs from the two modest pensions I have......the fact that one of these two pensions has had the P45 from my last employer included in it suggests to me that I might get charged tax twice for the 2 months from my last employer as that gross figure is currebtly ALSO showing in the payslips from one of the pension providers. Effectively that pensions providers paylsips look like I have recived money from that pension provider that I have not received.