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HMRC internal manual

Inheritance Tax Manual

Communications: Outgoing correspondence: postal system for mainland UK, Northern Ireland, Channel Islands and Isle of Man

All post to that is not sent through the -British Document Exchange (DX) (IHTM02141) system is sent by second class mail.

You should only send post first class in exceptional circumstances, such as where:

  • the parties ask for comments on a draft document only a few days ahead of a deadline, for example where there is an application to the Court
  • delay of even two or three days may cause loss to the estate, such as where securities have to be sold in a falling market
  • original documents that are urgently required for another purpose are being returned.

If you need to send any item of post first class because it is urgent you should take the letter by hand to the post room and ask them to send it first class.