HMRC required resubmission of SA100 in Mar 2022 after I submitted SA100 by post in Oct 2021It was my first self-assessment. I did not managed to have the UTR & NINO before the submission deadline. I submitted SA100 on 29 Oct 2021 by post and received acknowledge of receipt from HMRC on 1 Nov 2021. However, I have just received a letter from HMRC today (23/3) enclosing another SA100 requiring me to complete and return with the reminder that 31 Oct is the paper filing deadline. Why do I need to resubmit the SA100? Will a late-filing penalty be imposed?