Deceased father's paper tax return

We have submitted a paper tax return for my late father in June this year, as you cannot do it online for a deceased person. We have yet to receive confirmation from HMRC that this has been received (3 months later). The deadline is 31st October, which we were well within, but what if it hasn't been received? How would we know?

Hi,
You can find out when you can expect to receive a reply from HMRC at Check when you can expect a reply from HMRC.
You can also contact HMRC to check on the progress Self Assessment: general enquiries
Thank you.