We have been aware of issues sending regarding  sending tracked items to HMRC for some time and have covered this is past blog articles. We are still seeing the majority of items sent to HMRC with tracked services not showing any tracking updates and simply stating that they are “in transit” on the Royal Mail tracking. Previously we had advised our customers to use Special Delivery to send items but we are now finding that this service also fails to return any confirmation of delivery to HMRC addresses. 
  We would now advise customers not to use a tracked service to send items to HMRC and other government addresses such as DVLA and Companies House that receive a lot of mail as it is unlikely you will receive any delivery confirmation for your item. Tracked services can still be used as proof of posting, as they will show that we have dispatched the item but we do not expect them to provide a confirmation of delivery so would advise customers to use 1st or 2nd class mail for HMRC addresses.