IHTM25291 | Contracts for sale: Introduction
From HM Revenue & Customs · Inheritance Tax Manual
Property subject to a binding contract for sale is not relevant business property (IHTM25141) except where it is
a business or an interest in a business and the sale is to a company which is to carry on the business and is made wholly or mainly in consideration of shares in or securities of that company, or
shares in or securities of a company, and the sale is made for the purposes of reconstruction or amalgamation, IHTA84/S113.