The £1.2 Million Mistake: What One Family’s Inheritance Tax Crisis Reveals About Getting Estate Planning Right

For many families, inheritance tax planning is not about minimising a number on a balance sheet. It is about preserving something far more personal. A home that has been lived in for generations. Land that carries history as much as value. A business that represents decades of work.

That was very much the position facing the Fortescue family, custodians of the historic Boconnoc Estate in Cornwall.

In 2000, Elizabeth Fortescue and her husband Anthony began what would become a twelve-year, multi-million-pound restoration of the estate. This was not a short-term project, nor a purely commercial exercise. It was an effort to secure the future of something that mattered deeply, ultimately positioning the estate as a luxury wedding venue capable of sustaining itself for generations to come. By the time the work was complete, a huge amount of time, money and personal commitment had been invested in putting it on a stable footing.

When Anthony died in 2015, Elizabeth inherited a life interest in the trusts through which the estate was held. Like many families in a similar position, she was faced with a familiar but complex question. How do you begin passing value down to the next generation without triggering an immediate and potentially damaging inheritance tax charge?

A sensible plan

In 2017, Elizabeth took professional advice. The objective was straightforward and entirely legitimate. She wished to release part of her interest in the trust, specifically in relation to properties valued at around £4.4 million, in favour of her daughter Claire.

The intended outcome was that this would be treated as a potentially exempt transfer. In simple terms, provided Elizabeth survived for seven years, the value would fall outside her estate for inheritance tax purposes. There is nothing artificial about that approach. It is a well-established and widely used form of tax mitigation.

The advice itself, as the court later observed, appears to have been correct. What followed was not a failure of strategy, but a failure in how that strategy was carried through in legal and tax terms.

Where it went wrong

To give effect to the plan, legal steps were taken to release Elizabeth’s life interest and advance the relevant assets. The intention was that this would operate, in substance, as a lifetime gift by Elizabeth, falling outside her estate after seven years.

However, the structure and sequencing of those steps did not achieve that outcome.

Instead of being treated as a potentially exempt transfer made by Elizabeth in her personal capacity, the arrangement operated within the trust framework in a way that triggered an immediate inheritance tax charge. In effect, the transaction was treated as a chargeable transfer out of the trust, rather than a straightforward lifetime gift.

That distinction is easy to overlook, but critical in practice. Where assets are held in trust, the tax treatment depends not only on what is being done, but on who is treated as making the transfer and in what capacity. A life tenant cannot simply be equated with an outright owner for inheritance tax purposes. The mechanics of releasing an interest, and the way in which trustees then act, must align precisely with the intended tax analysis.

In this case, they did not.

As the judge later observed, the advice Elizabeth had received about the tax position was not the issue. The difficulty lay in the way the transaction had been implemented. The process used to give effect to the plan was both wrong and unnecessary, and in turn created an immediate 20 percent inheritance tax charge, resulting in a liability of approximately £1.2 million.

This is where even well-advised planning can unravel. The interaction between trust law and inheritance tax legislation is highly technical. A step taken in the wrong capacity, or structured in a way that inadvertently brings the trustees into the transaction, can fundamentally change how the transfer is taxed. That is precisely what happened here.

The real-world consequences

An unexpected £1.2 million tax bill is not simply an accounting issue.

The Boconnoc Estate, like many long-held family estates, is asset-rich but not cash-rich. Its value is tied up in land and property rather than readily available funds. Meeting a liability of this scale would likely have required the sale of estate assets, undoing years of careful restoration and potentially compromising the long-term viability of the estate itself.

This was not aggressive tax planning backfiring. It was a genuine mistake, made in the course of trying to preserve a family legacy. Elizabeth herself accepted that, had she understood the true effect of the steps taken, she would not have proceeded.

The court recognised that. It accepted that she had acted under a fundamental misunderstanding as to the tax consequences, and that the impact was sufficiently serious to justify intervention. Describing the outcome as an unintended tax consequence and a particularly grave error in the context of a carefully managed estate, the judge concluded that it would be unconscionable not to set the transaction aside.

The deeds were unwound. The £1.2 million liability was removed.

Why this could have ended very differently

The ability to set aside a transaction for mistake is a narrow and highly fact-specific remedy. It requires clear evidence that the individual entered the arrangement under a fundamental misunderstanding, and that the consequences are sufficiently serious to warrant undoing it.

Even then, success is not guaranteed. The process requires litigation, with all the cost, time and uncertainty that entails.

What should have happened

At its core, this case turns on a disconnect between tax advice and legal execution.

A more robust process would have ensured that the way Elizabeth’s interest was released delivered the intended tax result in practice, not just in principle. That requires more than identifying the desired outcome. It involves carefully structuring each step so that, taken together, they achieve that outcome without creating unintended consequences.

In a case such as this, particular care is needed to distinguish between a transfer made personally by a life tenant, a transfer made by trustees within the trust structure, and any step which might trigger an immediate tax charge. Each of these is treated differently for inheritance tax purposes.

The process should therefore have been handled as a single, coordinated exercise. The release of the life interest and the onward transfer of assets needed to be aligned clearly with the intended tax treatment, supported by precise drafting and careful sequencing.

Just as importantly, the proposed structure should have been fully tested before any steps were taken. That means checking how the arrangement would be treated under the relevant inheritance tax rules and ensuring that the documentation reflected that analysis without ambiguity.

Had that level of coordination and oversight been applied, the risk of the transaction being treated as a chargeable transfer within the trust could have been identified and avoided before any documents were executed.

Looking ahead

While the Boconnoc Estate is exceptional in its history, the issues it raises are not.

More families are engaging in lifetime planning, particularly in the context of rising asset values and long-standing inheritance tax thresholds. Trusts, life interests and intergenerational transfers are increasingly common. With that comes a growing risk, not necessarily of poor advice, but of imperfect implementation.

The difference between a successful strategy and a costly mistake can lie in details that are easy to overlook without the right level of specialist oversight.

At Buckles, we understand that effective inheritance tax planning is not simply about identifying the right strategy, but ensuring that it is carried through with care and precision. We work closely with clients and their wider advisers to align tax advice with legal implementation, overseeing each stage so that the intended outcome is achieved in practice. That includes structuring and reviewing trust arrangements, managing the documentation, and ensuring that changes are implemented in a way that reflects both the legal framework and the client’s long-term objectives. We also recognise that estates evolve over time, and that planning must be kept under review as circumstances change. Where things do go awry, as in the Fortescue case, our team of Wills, Trusts and Estate Dispute Specialists are available to provide assistance as to the appropriate actions and applications to attempt to recover the position.

The Fortescue case is a powerful reminder of what is at stake. Years of careful stewardship, and a clear intention to preserve a family legacy, were placed at risk by a single flawed process. For families seeking to protect significant wealth, getting that process right is not a detail. It is everything.

The content of this article is intended to provide a general guide to the subject matter. Specialist advice should be sought about your specific circumstances.