I also have a problem with P45. I left my last job on 1st May 2023 and started my new job on around 20 May 2023. My previous employer did not issue me a P45 and neither informed HMRC that I left the job. I now ended up paying too much tax for the past 6 months. I have called HMRC and they told me they had no record of me leaving my previous job and that I must provide them with a P45. So I have now requested the P45 which I have with me. I have called HMRC after being in the queue for more than an 1 hour and they said my employer should deal with it. My employer told me they cant and I must send the P45 to HMRC directly. Can you please let me know where do I send this? I only work part time and I am a mother and on a salary of £600 a month I been paying almost £200 of tax every month. I need this money back please.