ACCA TX-UK: Three Places Lifetime IHT Calculations Go Wrong

Lifetime inheritance tax (IHT) questions in ACCA Taxation (TX-UK) rarely fail candidates on a single rule in isolation — most candidates know the nil rate band, the annual exemption, and the basic chargeable lifetime transfer mechanics. Where marks are lost is in the interactions between rules, particularly when a question deliberately combines two areas that are each simple individually but easy to get wrong together. For a fuller view of how the paper as a whole is structured and marked, see our guide to passing ACCA TX.

Trap one: excluding ISAs from the death estate

Individual Savings Accounts (ISAs) are a tax-free wrapper for income tax and capital gains tax purposes, and this tax-free status leads some candidates to assume ISAs are also excluded from a person's estate for IHT purposes. They are not. ISA tax advantages are specifically about income and gains generated within the wrapper during the account holder's lifetime — they say nothing about the value of the ISA on death. The full value of any ISA holdings is included within the death estate for IHT purposes, the same as any other investment the deceased owned. Candidates who instinctively exclude ISAs because they're "tax-free" are conflating two entirely separate tax treatments — our guide to inheritance tax for accountants and finance professionals covers how the death estate is assembled in full.

Trap two: grossing-up only applies when the transferee bears the tax

Grossing-up (commonly using the 20/80ths formula, since lifetime chargeable transfers above the nil rate band are generally taxed at 20% rather than the 40% death rate) is a mechanic many candidates apply automatically to lifetime transfers, without checking who is actually liable for the tax. Grossing-up is only relevant where the transferee (for example, a trust) agrees to bear the IHT due on the transfer, meaning the amount transferred needs to be grossed up so that, after tax, the trust still receives the intended net amount. Where the donor pays the tax personally, there's no grossing-up requirement — the tax is simply calculated on the value transferred. Applying the grossing-up formula automatically, regardless of who is stated as liable for the tax in the question, is one of the most consistent sources of lost marks in this area, because it changes the tax base the rate is applied to.

Trap three: the same shareholding needs a different value for CGT and for IHT

Where a question involves the same shareholding being both a lifetime gift (relevant for IHT) and a disposal for capital gains tax purposes, candidates sometimes assume a single share value can be used across both calculations. It cannot. Capital gains tax uses the quoted share valuation rules under TCGA 1992 (broadly, the lower of two specified quarter-up/average calculations for quoted shares), while inheritance tax uses the open market value of the shares at the date of transfer, which for unquoted or closely-held shares in particular can be a materially different figure, reflecting different valuation principles built for different purposes. A question testing both taxes on the same lifetime gift is specifically probing whether candidates recognise that CGT and IHT don't share a single "correct" value for the same asset on the same day — they each apply their own valuation basis.

Why these three sit together as a pattern

What links all three traps is the same underlying examiner strategy: taking a rule most candidates know in isolation and testing whether they also know its scope and its interactions with adjacent rules. Knowing that ISAs exist, that grossing-up exists, and that share valuation rules exist isn't sufficient — scoring well requires knowing precisely when each applies and, just as importantly, when it doesn't. This is a deliberate design feature of higher-skill TX-UK questions rather than an accident of question-writing, and it rewards candidates who pause to check the specific facts of a scenario against the boundary conditions of a rule, rather than pattern-matching to the first rule that seems relevant.

Building the habit of asking "does this specific fact pattern actually meet the conditions for this rule" — rather than assuming a rule applies because the general topic area is IHT — is what separates strong TX-UK scripts from ones that know the syllabus but lose marks on application.

Frequently asked questions

Are ISAs excluded from a person's estate for inheritance tax purposes?

No. ISAs are tax-free for income tax and capital gains tax during the holder's lifetime, but their full value is included in the death estate for inheritance tax purposes, the same as other investments.

When does grossing-up apply to a lifetime chargeable transfer?

Only when the transferee (such as a trust) agrees to bear the inheritance tax due on the transfer. Where the donor pays the tax themselves, grossing-up doesn't apply, and the tax is calculated directly on the value transferred.

Do capital gains tax and inheritance tax use the same value for a gifted shareholding?

No. CGT uses the specific quoted share valuation rules under TCGA 1992, while IHT uses open market value at the date of transfer — these can produce materially different figures, particularly for unquoted shares.

Lifetime IHT questions in TX-UK are ultimately testing precision about scope and interaction, not raw recall of the rules — the nil rate band, the nature of chargeable transfers, and grossing-up are all straightforward on their own, but combining them correctly with adjacent rules under exam pressure is where the real skill is assessed. Learnsignal's ACCA TX-UK course covers inheritance tax alongside the full UK taxation syllabus.