A Flexible Life Interest Trust is not purely discretionary; it is a hybrid. During the life tenant’s lifetime, it functions as a life interest trust, giving the life tenant guaranteed rights to income or use of assets. On the life tenant’s death, it converts automatically into a discretionary trust for the remaining beneficiaries. This distinction has significant implications for inheritance tax planning and beneficiary rights, and our team at Paradigm Wills regularly explains it to clients when helping them choose the right structure.

What Is a Flexible Life Interest Trust (FLIT)?

A flexible life interest trust FLIT combines two distinct trust structures into one arrangement. It is most commonly used in wills, particularly when one spouse or partner wants to protect the other during their lifetime while ensuring assets ultimately pass to children or other beneficiaries.

The “flexible” element refers to the trustees’ ability to adapt the trust’s operation over time. They can, within defined parameters, distribute income or even capital to the life tenant, the person who holds the right to benefit from the trust during their lifetime or make adjustments as circumstances change.

This flexibility creates confusion with discretionary trusts. The trustees do exercise discretion, but that discretion operates within a framework that is fundamentally different from a pure discretionary trust. When Paradigm Wills drafts a FLIT, we set out exactly where that discretion begins and ends, so your trustees and beneficiaries face no ambiguity.

What Is a Discretionary Trust, and How Does It Differ?

In a discretionary trust, no single beneficiary holds an automatic, legally enforceable right to income or capital. The trustees have complete discretion over how, when, and to whom they make distributions. Trustees decide everything, and no beneficiary can compel a payment. We explain this in more depth in our guide to what a discretionary trust in a will actually does.

This structure offers considerable flexibility for estate planning, particularly in blended family situations or where beneficiaries’ needs are difficult to predict. However, it also means that no beneficiary has certainty of benefit.

A life interest trust, by contrast, gives the life tenant a fixed, enforceable right to receive income from the trust assets, or to occupy a property, for as long as they are alive. The trustees cannot withhold that benefit; the trust deed guarantees it. If you are weighing this option, our article on whether a person with a life interest can sell the property is a useful companion read.

The FLIT sits between these two models. It preserves the life tenant’s guaranteed entitlement during their lifetime, while building in discretionary powers that allow trustees to respond to changing circumstances, including the option to advance capital to the life tenant where the trust deed permits.

How Does the “Switch” Work When the Life Tenant Dies?

The defining structural feature of a FLIT is what happens when the life tenant dies. At that point, the trust does not simply distribute assets to named beneficiaries in fixed shares. Instead, it converts into a fully discretionary trust. In practice, this is the stage where clients most often ask us to walk them through what their trustees can and cannot do, so here is the sequence in plain terms:

• While the life tenant is alive, the trust runs on life interest principles: the life tenant has a guaranteed right to income or to occupy the property, and the trustees cannot redirect that benefit away from them.
• On the life tenant’s death, the guaranteed interest ends and the discretionary phase begins automatically; no separate deed or court step is required, provided the trust has been drafted correctly.
• Once the life tenant is no longer alive, the trustees take over full control, exercising their discretion to decide how, when, and to whom the remaining assets are distributed.
• The class of beneficiaries typically includes children, grandchildren, or other family members named in the original trust deed, then looks to the trustees rather than to any fixed entitlement.

This is the source of the most common misunderstanding. People see the discretionary element and assume the whole trust is discretionary. In practice, the discretionary phase only begins after the life tenant’s death. While the life tenant is alive, the trust is governed by life interest principles, not discretionary ones.

IHT Treatment: While the Life Tenant Is Alive

The IHT liability position of a FLIT depends entirely on the trust’s phase.

During the life tenant’s lifetime, a FLIT created on death is typically classified as an Immediate Post-Death Interest (IPDI) for inheritance tax purposes. This classification, set out in the Finance Act 2006 and the Inheritance Tax Act 1984, means the life tenant retains that interest during their lifetime and will be treated as the main beneficiary for IHT purposes, effectively as if they own the underlying trust assets outright.

The practical consequence is significant: if the life tenant is the deceased’s surviving spouse or civil partner, the spousal exemption from inheritance tax applies. Assets passing into the FLIT on death are exempt from IHT, and the life tenant’s nil-rate band position is preserved, including the transferable nil-rate band.

This is one of the primary reasons FLITs are used in estate planning. They allow a testator to protect a surviving spouse without triggering an immediate IHT charge, while still controlling the estate’s ultimate destination. Getting that balance right from the outset is exactly what our inheritance tax planning work is built around.

IHT Treatment: After the Life Tenant Dies

When the life tenant dies, the trust transitions into the discretionary phase, and the IHT treatment changes accordingly.

At this point, the trust falls within what HMRC terms the “relevant property regime.” Under this regime, the trust fund is subject to periodic charges assessed every ten years at up to 6% of the trust’s value above the nil-rate band, plus exit charges when assets leave the trust. The Inheritance Tax Act 1984 outlines these charges, and HMRC administers them.

It is worth noting that the transition itself, the life tenant’s death, is a chargeable event for IHT. At that point, the trust assets are treated as part of the life tenant’s estate, which may trigger an IHT liability depending on the overall estate value and available exemptions.

This is why professional advice at the drafting stage is important. The interaction between the IPDI phase and the subsequent relevant property regime requires careful consideration to avoid unintended tax consequences, and it is one of the most common inheritance tax planning mistakes we help clients avoid.

Discretionary Trust vs Life Interest Trust vs FLIT: Key Differences

Understanding how these three structures compare helps clarify why a FLIT is genuinely distinct. The table below sets out the three most important dimensions: beneficiary rights, trustee discretion, and IHT treatment.

If you are unsure which column best fits your family, that is precisely the conversation our trusts team has with clients every week.

Who Is a FLIT Suited To?

The FLIT’s hybrid structure makes it particularly well-suited to specific personal and family circumstances.

Second marriages and blended families represent the most common use case. A testator may want to provide financial security for a second spouse during that spouse’s lifetime, while ensuring that assets ultimately pass to children from a prior relationship rather than into the second spouse’s estate. A FLIT achieves both objectives within a single structure, without relying on the surviving spouse’s goodwill or future testamentary decisions. For unmarried partners, the position is slightly different, and we explain how the structure adapts in our guide to whether a Flexible Life Interest Trust can work for a cohabitee.

Care planning is another relevant scenario. If there is a concern that a surviving spouse may require residential care later in life, the trust structure means assets held within the FLIT are not automatically treated as the spouse’s own assets for local authority means-testing purposes, depending on how the trust is drafted and administered. This is a complex area, and the position varies depending on the specific facts and the local authority’s assessment. It often sits alongside a Protective Property Trust, which we use to help clients ring-fence the family home.

Protecting against third-party claims is a further consideration. Assets held in trust are generally outside the life tenant’s estate for the purposes of creditor claims or party claims arising from future relationships or divorce proceedings. This can be particularly relevant where beneficiaries are young adults whose circumstances may change significantly over time.

A pure discretionary trust may suit situations where the testator cannot predict which beneficiaries will have the greatest need, or where all beneficiaries are adults with variable financial circumstances. A straightforward life interest trust may be preferable where simplicity and certainty of benefit are the primary objectives and the IHT position is already well-managed. If you are still deciding whether a trust is the right route, our article on setting up a trust instead of just writing a will is a good starting point.

What Are the Flexible Life Interest Trust Pros and Cons?

Flexible Life Interest Trust pros and cons are worth examining directly, as the structure carries both clear advantages and genuine limitations.

Advantages include:

• Spousal IHT exemption preserved during the IPDI phase, reducing the immediate tax burden on the estate.
• The life tenant’s financial security is guaranteed for their lifetime, which a discretionary trust cannot offer.
• Trustees retain the ability to respond to changing circumstances, including advancing capital to the life tenant where the trust deed permits and exercising their discretion over distributions to remaining beneficiaries after the life tenant’s death.
• The structure can protect assets from third-party claims and care cost assessments, subject to how the trust is drafted.

Limitations include:

• The transition to the relevant property regime on the life tenant’s death introduces periodic and exit charges that do not apply during the IPDI phase.
• The trust requires active administration, including accurate record-keeping and periodic IHT reporting to HMRC.
• Drafting a FLIT correctly requires specialist legal input; an incorrectly drafted trust may not achieve the intended tax treatment or may fail to qualify as an IPDI. This is where working with an experienced team such as Paradigm Wills makes the difference.
• The life tenant’s guaranteed entitlement means trustees cannot simply redirect income away from the life tenant during their lifetime, even if circumstances change significantly.

Types of Trusts: Placing the FLIT in Context

Among the main types of trusts used in UK estate planning, the FLIT occupies a specific and well-defined position. To see where it fits:

• It is not interchangeable with a discretionary trust. The discretionary element only applies after the life tenant’s death, a point worth reading alongside our explainer on what is meant by a discretionary trust.
• It is not simply a life interest trust with added features. It is designed to deliver the benefits of both approaches across two sequential phases, with the IHT treatment shifting accordingly.
• The right choice depends on three factors: the family’s composition, the size and nature of the estate, and the testator’s priorities regarding control, certainty, and tax efficiency.
• It is most valuable when the testator needs to balance the competing interests of a surviving spouse, children, or other beneficiaries, particularly in second marriage or blended family situations.
• Whichever structure is appropriate, the drafting must be precise. The difference between an IPDI and a discretionary trust is not merely semantic it determines the IHT treatment, the beneficiaries’ legal rights, and the trustees’ obligations for the entire life of the trust.

To get an overview of how a trust fund is structured and set up in the UK, our step-by-step guide is a good place to begin, and you can browse the full range of trusts we offer to see how each one is used in practice.

Ready to Discuss Your Trust Planning Options?

Our team at Paradigm Wills and Legal Services works with clients across Leicester, London, Birmingham, and beyond to draft wills and trusts that reflect their specific family circumstances and estate planning objectives. If you are considering a Flexible Life Interest Trust, a Discretionary Trust, or any other trust arrangement, we offer no-obligation consultations designed to give you clear, practical guidance from the outset.

Protecting your legacy shouldn’t feel complicated. Call our Leicester office on 0116 464 7055 or get in touch to take the first step. We are here to make the process straightforward from your very first conversation.