IHTM14825 | Lifetime transfers: associated operations: additional provisions
From HM Revenue & Customs · Inheritance Tax Manual
As a general rule, it does not matter whether or not
the operations (IHTM14826) are effected by the same person or
they are effected simultaneously.
There are two exceptions from this general rule. These exceptions are set out in IHTA84/268(2). The exceptions are that
the granting of a lease for full consideration in money or money’s worth cannot be associated with an operation which occurs more than three years later.
an operation effected before 27 March 1974 cannot be associated with one which occurs on or after that date.