Several postal items lost by Hmrc

In the past 3 months I have sent a Trust tax return and a personal tax return to Hmrc by ‘signed for’ Royal Mail post. Both are shown on Royal Mail tracking as being delivered to the relevant Hmrc post codes. As I heard nothing back after several weeks I phoned Hmrc (one call to the Trust dept, one to the personal dept) to be told that neither of these returns are showing on the Hmrc system. The same thing happened to the Trust tax return I sent last year. I keep being told that this is very unusual but my experience is that 3 out of 4 submissions have gone missing. Both the Trust return and the personal return (as it involves Trust income) cannot be done online. This situation is immensely frustrating, expensive and time consuming. Why is the Hmrc post handling so inefficient?

Hi,
If the tax returns were sent by recorded delivery and you have the reference number then when you contact HMRC, a referral can be sent to trace the tax return if not yet noted on the record.
Self Assessment: general enquiries
Thank you.