IHTM31016 | Assessing: calculation principles: the tax calculation (settlement cases)
From HM Revenue & Customs · Inheritance Tax Manual
You can prepare some settlement calculations on COMPASS (), but the remainder must be calculated manually.
The later instructions provide advice on calculations relating to
immediately chargeable transfers ()
principal, proportionate and flat rate charges () in existing settlement cases, and
recapture charges () when heritage property or timber is disposed of.