How to fill in form IHT415: interest in another estate, explained
IHT415 reports an inheritance the deceased was entitled to but had not received when they died — money, a specific item, or a share of someone else's estate.
Because the earlier estate hadn't finished paying out, that unreceived entitlement is itself an asset of the deceased's own estate, and its value has to be included in the IHT400 account.
This walkthrough explains the double-death scenario in plain English, box by box: who the 'predecessor' is, how to value land, business interests and shares versus everything else, and how IHT415 differs from the separate quick succession relief claim (IHT416) that families often confuse it with.
United Kingdom·Informational, not legal or financial advice·Verified against GOV.UK, 2026
This walkthrough takes IHT415 field by field, in plain English. The form itself is short — ten boxes across three pages; the part that actually takes time is finding the earlier estate's paperwork and putting a fair value on something that hasn't been paid out yet.
Confusing this with quick succession relief
IHT415 and quick succession relief (claimed on a separate schedule, IHT416) both deal with two deaths close together, but they do different jobs and families regularly conflate them.
IHT415 makes sure a right the deceased never actually received is correctly valued and included in their own estate — it applies whenever the earlier estate hadn't finished paying out, however long ago the first death was, even decades.
Quick succession relief instead gives a tapering tax credit where an asset that did reach the deceased would otherwise be taxed twice within 5 years of the two deaths.
A family can need both forms for the same pair of deaths: IHT415 to value what's still owed, IHT416 to claim relief on what's already been received.
The form, in summary
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IHT415·3 pages·16 fields guided
With Valoren30–40 minutes
Without Valoren1–3 hours
tracking down the earlier estate's executor and getting a value for an entitlement that hasn't been paid out is the slow part, not the form itself
IHT415 is filed with IHT400 whenever the deceased had a right to a legacy or a share in someone else's estate — the 'predecessor', who died earlier — but had not received it before they themselves died.
Because the earlier estate had not finished paying out, that right is not yet an interest in any specific asset: it is a chose in action, a right to require the earlier estate to be properly administered and to receive the correct share of it. Case law treats it that way (Commissioner of Stamp Duties (Queensland) v Livingston [1965] AC 694), which is why the form asks you to value it as a net figure — assets less liabilities of the earlier, still-unadministered estate — rather than list specific inherited items as though they were already the deceased's own.
A separate IHT415 is required for each earlier estate in which the deceased held such a right. The most common confusion is with quick succession relief (IHT416): that is a different, tapering relief for tax paid twice on the same value within 5 years, claimed on a separate schedule and often needed alongside — not instead of — IHT415.
·Who Files — The executor (if there is a will) or the administrator (if there is no will) of the deceased's own estate — not anyone connected with the earlier, predeceased person's estate
·3 pages · 16 fields guided
·Draws from your Estate File — Kinship & Succession Map, Legal Instruments, Financial Accounts
Section01
§11
Section 1
What IHT415 is for — the second death, explained plainly
IHT415 exists for a specific, easily-confused situation: two deaths, in a known order, where the second person died before an inheritance from the first had actually reached them.
This is not the same as commorientes (deaths so close together the order is legally uncertain, governed by a survivorship presumption) — here the order of death is clear, and the gap can be years.
01
The plain-English version
Person A dies and leaves money, an item, or a share of their estate to Person B. Before A's estate finishes paying out, B also dies. B's own estate must now include the value of what B was owed from A's estate, even though B never actually received it.
02
Why HMRC needs to know
A right to an unreceived inheritance is still an asset — it has value, even if that value is only realised later when A's estate finally pays out. If it were left off B's estate, tax would effectively never be paid on that value passing through B's own estate to B's beneficiaries.
03
One form per earlier estate
If the deceased was owed something from more than one earlier estate, fill in a separate IHT415 for each one. Each form only ever describes a single 'predecessor' relationship.
IHT415 exists for a specific, easily-confused situation: two deaths, in a known order, where the second person died before an inheritance from the first had actually reached them.
This is not the same as commorientes (deaths so close together the order is legally uncertain, governed by a survivorship presumption) — here the order of death is clear, and the gap can be years.
HM Revenue & Customs (HMRC) · IHT415❦
Section02
§22
Section 2
Details of the person who died earlier — boxes 1 to 3
This section identifies the predecessor — the person who died first — and the earlier estate itself, separately from the header details of the deceased (name, date of death, IHT reference) that sit at the top of page 1.
01
Box 1 — the predecessor's name
Title, surname and first names of the person who died earlier. This can be a spouse, parent, sibling, friend — anyone the deceased had an outstanding entitlement from.
02
Box 2 — date the predecessor died
The date of the earlier death. There's no limit on how long ago this can have been; what matters is whether the estate had finished paying out the deceased's share before the deceased's own death.
03
Box 3 — the earlier estate's reference, or the date of grant
Give the Capital Taxes or Inheritance Tax reference for the earlier estate if it's known. If not, give the date of grant for the earlier death instead — either lets HMRC find the earlier file if they need to cross-check the claim.
This section identifies the predecessor — the person who died first — and the earlier estate itself, separately from the header details of the deceased (name, date of death, IHT reference) that sit at the top of page 1.
HM Revenue & Customs (HMRC) · IHT415❦
Section03
§33
Section 3
The deceased's entitlement — boxes 4 to 6
This section establishes what, exactly, the deceased was owed, and whether any of it had already reached them before they died.
01
Box 4 — what the deceased was entitled to
Describe the entitlement: for example, a legacy of money, a specific item, or a share of the predecessor's residuary estate. Be as specific as the will or intestacy rules of the earlier estate allow — this description sets up the valuation in boxes 7–9.
02
Box 5 — had the deceased received any part of it?
A simple yes/no gate. Answer 'No' and the form sends you straight to box 7 on page 2. Answer 'Yes' and box 6 asks what had already been received — the received portion is accounted for as the deceased's own asset elsewhere, not on this schedule.
03
Box 6 — what had already been received
Only completed if box 5 is 'Yes'. Describe what the deceased had actually received from the earlier estate before they died, so it's clear what remains to be valued as still-outstanding in the boxes that follow.
This section establishes what, exactly, the deceased was owed, and whether any of it had already reached them before they died.
HM Revenue & Customs (HMRC) · IHT415❦
Section04
§44
Section 4
Valuing the entitlement — boxes 7 to 10
The form splits the still-outstanding entitlement into two categories, each with its own net-value table and its own destination on IHT400 — this split matters for how HMRC's instalment-option rules apply to the underlying assets.
01
Box 7 — houses, land, business interests, controlling shareholdings
Use this box for the deceased's entitlement to houses, land and buildings; an interest in a business; or shares or securities that gave the deceased control of the company. List debts or liabilities due on these assets in the same box, and enter the net value.
The total from this box is copied to box 71 of IHT400 — HMRC's own manual (IHTM10105) confirms the box 71/72 split.
02
Box 8 — are the box 7 values estimates?
A yes/no flag. HMRC expects your best figures, but accepts that a genuinely unadministered estate may only support an estimate at this stage.
03
Box 9 — everything else
All other assets the deceased was entitled to that aren't already covered by box 7 — cash, personal possessions, investments that don't carry company control, and so on. List debts or liabilities against these assets in the same box, and enter the net value. The total from this box is copied to box 72 of IHT400.
04
Box 10 — are the box 9 values estimates?
The same yes/no flag as box 8, applied to the box 9 figures.
The form splits the still-outstanding entitlement into two categories, each with its own net-value table and its own destination on IHT400 — this split matters for how HMRC's instalment-option rules apply to the underlying assets.
HM Revenue & Customs (HMRC) · IHT415❦
Section05
§55
Section 5
The relief people confuse this with — quick succession relief (IHT416)
IHT415 and quick succession relief solve different problems, but because both involve two deaths in quick succession, executors regularly reach for the wrong one — or miss that they may need both.
01
What quick succession relief actually does
Where an asset was taxed on the first death and the same value would otherwise be taxed again on the second death within 5 years, quick succession relief gives a tapering credit against the tax on the second death: broadly 100% relief within 1 year, reducing in steps to 20% in the fifth year, and none after 5 years.
02
It's claimed on a different schedule
Quick succession relief has its own form, IHT416, with its own worksheet — the resulting figure goes into a different box on IHT400 from the IHT415 totals. Filing IHT415 does not automatically claim quick succession relief, and vice versa.
03
When you need both
If the deceased received part of the inheritance from the earlier estate (potentially eligible for quick succession relief) and was still owed the rest when they died (reportable on IHT415), the same pair of deaths can need both forms — one for what came through, one for what didn't.
IHT415 and quick succession relief solve different problems, but because both involve two deaths in quick succession, executors regularly reach for the wrong one — or miss that they may need both.
HM Revenue & Customs (HMRC) · IHT415❦
Many people file IHT415 themselves — that is what this walkthrough is for. If the estate behind it has stopped being simple — inheritance tax to pay, a trust, foreign assets, a dispute — Signum, Valoren’s own specialist desk, can take it on, and we say so plainly: it starts with a free intake, and if you do not need us, we will tell you. Prefer an independent adviser? STEP and the Chartered Institute of Taxation both keep public member directories, and neither pays Valoren a referral fee.
FAQ
IHT415 questions, answered.
01What is form IHT415 for?›
IHT415 is the HMRC schedule filed with IHT400 when the deceased had a right to a legacy or share in someone else's estate — the 'predecessor' — but died before receiving it.
The value of that unreceived entitlement is added to the deceased's own estate for inheritance tax, using the figures set out on the schedule.
02Who counts as 'the person who died earlier'?›
The predecessor is the person who died first — the one whose estate still owed the deceased their inheritance.
They can have died months or years before the deceased — the form asks for their name, date of death, and the earlier estate's Capital Taxes or IHT reference, or the date of grant if the reference isn't known.
03What if the deceased had already received part of the inheritance?›
Box 6 records what was already received before death — that part is treated as one of the deceased's own assets in the normal way, reported elsewhere on IHT400, not on this schedule.
Any part still outstanding at death goes in box 7 or box 9 instead, valued as at the deceased's own date of death.
04How do I value an entitlement that hasn't been paid out yet?›
Value it the way you'd value the deceased's own assets — at its worth on the deceased's date of death, not the predecessor's.
For a share of residue, that means listing the assets and liabilities the earlier estate's personal representatives still held at that date, deducting any legacies still to be paid, and showing the resulting net figure.
If you can't get exact figures before applying for the grant, HMRC accepts a reasonable estimate — boxes 8 and 10 ask you to flag which figures are estimates.
05Is IHT415 the same as quick succession relief?›
No — they do different jobs in the same situation.
IHT415 makes sure an inheritance the deceased never received is correctly valued and included in their own estate.
Quick succession relief, claimed on a separate schedule (IHT416), instead reduces the tax due where an asset was taxed on the first death and would otherwise be taxed again within 5 years on the second.
A family can need both forms for the same pair of deaths.
06Do I need a separate IHT415 for each earlier estate?›
Yes. HMRC asks for a separate IHT415 for each estate in which the deceased held an outstanding right to a legacy or share — so if the deceased was owed money from two different earlier deaths, two forms are needed.
07What if the earlier estate's administration still isn't finished?›
That's expected, and the form is built for it. Boxes 7 and 9 ask for the assets and liabilities the earlier estate's personal representatives held at the deceased's date of death, not a finished, settled figure.
Give the best information available, including an estimate where needed, rather than waiting for the earlier estate to close.
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Where this fits
IHT415 is one form. The file behind it is the rest.
Tracing an unreceived entitlement means finding the earlier estate's grant, its executor, and what — if anything — was actually paid out before the second death.
The Kinship & Succession Map records who predeceased whom and in what order; Legal Instruments holds a copy of the earlier will or grant if one survives in the family's papers.
When you're ready — not before — our £179 Executor's First Hour walks you through registering the death, notifying banks and pensions, and getting probate started, in the right order. The free checklist above covers the essentials; this is for when you'd rather have a hand to hold. Executor's First Hour — £179 →
HM Revenue & Customs (HMRC)·16 fields·No separate fee — this is a supplementary schedule filed with IHT400·30–40 minutes with Valoren
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