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HMRC internal manual

Inheritance Tax Manual

Interest in unadministered estates and QSR: introduction

Where a person is entitled to an interest in another person’s estate (IHTM04043) and they die before the administration of that earlier estate was completed you will need to calculate the value of the unadministered estate as part of the estate you are looking at now.

Where inheritance tax was payable in connection with the earlier death you may be able to allow some of that tax as a relief against the tax payable on the second estate. There is a similar relief on lifetime transfers (IHTM04051) on the termination prior to death of a qualifying interest in possession.

This section provides more detailed information and guidance about valuing an interest in an unadministered estate (IHTM22011) and calculating and allowing relief for successive charges known as Quick Succession Relief or QSR (IHTM22041).