IHTM26071 | Other calculations: order in which to apply the partly exempt transfer rules
From HM Revenue & Customs · Inheritance Tax Manual
To minimise the risk of making an error in a case involving more than one of the partly exempt transfer rules you need to apply them in the correct order. This order is as follows
Step 2 (IHTM26090) - If the total value of the specific gifts exceeds the value of the free estate , consider abatement (IHTM12086) under IHTA84/S37 (1)
Step 3 (IHTM26101) - If any business relief (IHTM25131) or agricultural relief (IHTM24001) has been allowed, apply the interaction (IHTM26103) rules in IHTA84/S39A to reduce the value of the specific gifts
Step 4 (IHTM26121) - Gross up the value of any chargeable specific gifts which do not bear their own tax. The value to gross up is the value after any reduction under Step 3
Step 5 (IHTM26180) - Compare the total value of the specific gifts (exempt and chargeable), with the value of the free estate after business relief and agricultural relief
if the total is less than the value of the estate, the difference is the value of the residue (IHTM12082), but
if the total exceeds the value of the estate after relief, there is no residue and you need to consider abatement under IHTA84/S37 (2).