Farra is a death administration assistant for UK families. Get step-by-step guidance for registering a death, applying for probate, notifying banks, and managing bereavement admin. From essential documents to practical checklists, Farra simplifies estate paperwork and funeral-related tasks so you can focus on what matters.
The IHT400 is HMRC's full inheritance tax account. You complete the main form, attach a schedule for each type of asset the estate holds, calculate the tax, then post the pack to HMRC within 12 months of the death. HMRC then sends you a unique code, and only once that arrives can you apply for probate. It is long but methodical: most of the work is gathering date-of-death valuations before you start.
You only complete the IHT400 when the estate is not an "excepted estate". For deaths on or after 1 January 2022, excepted estates no longer file a separate form at all. The old short form, IHT205, has gone. Instead, you simply report the estate's headline figures within the probate application itself.
Broadly, an estate is likely to need the full IHT400 if any of these apply (the GOV.UK checker gives a definitive answer):
Before starting, it helps to understand the allowances themselves. Our inheritance tax guide for 2026-27 covers the £325,000 nil-rate band and the residence nil-rate band of up to £175,000. The spouse exemption is unlimited in most cases, but from 6 April 2025 it is capped at the nil-rate band where the deceased was a long-term UK resident and the surviving spouse was not.
Gather these before beginning the form. For detailed guidance on property values, see our guide on valuing an estate for probate:
Create a spreadsheet listing all assets and debts. This becomes your reference and makes the arithmetic much easier to check.
The opening pages ask for basic information:
List all UK assets with values at the date of death:
Critical: use date-of-death values, not current values.
List gifts made in the 7 years before death:
Schedules are supplementary sheets, one per type of asset or claim. You only complete the ones that apply. We have detailed guides for the most common:
| Schedule | When Needed |
|---|---|
| IHT402 | Transferring unused nil-rate band from a late spouse |
| IHT403 | Gifts made in the last 7 years |
| IHT405 | UK houses, land and buildings (needed whenever there is property) |
| IHT406 | Bank, building society and NS&I accounts |
| IHT407 | Household goods, personal possessions and vehicles |
| IHT409 | Pensions |
| IHT410 | Life insurance and annuities |
| IHT411 | Listed stocks, shares and investments |
| IHT417 | Foreign assets |
| IHT419 | Debts owed by the deceased |
| IHT435 | Residence nil-rate band claim |
| IHT436 | Transferring unused RNRB from a late spouse |
A common combination: IHT400 + IHT405 + IHT406 + IHT407 + IHT419 + IHT435 for an estate with a house, bank accounts and a residence nil-rate band claim.
The IHT400 pack is submitted by post. Send the completed form and schedules to Inheritance Tax, HM Revenue and Customs, BX9 1HT. Tracked or recorded delivery is sensible, since the pack contains a lot of work you would not want to repeat.
The form must reach HMRC within 12 months of the date of death. HMRC's notes are blunt about what happens otherwise: sent in late without reasonable excuse, “you may be liable to a penalty up to £200”, and if the delay stretches to two years after the death, “an additional penalty up to £3,000”. That is a separate deadline from the six-month payment deadline below, and the two are easy to confuse.
Keep your valuations, bank letters and calculations on file. HMRC does not need every supporting document up front, but it can ask for evidence later, and you will want it to hand if a query arrives.
You cannot apply for probate straight away. HMRC sends a letter or email with a unique code confirming that enough tax has been paid, and GOV.UK says you will usually get it within 20 working days of HMRC receiving your IHT400 or your inheritance tax payment, whichever is later. The gate is the code, not the calendar: you cannot submit the application without it, and if 20 working days pass and nothing has arrived, ring the inheritance tax helpline on 0300 123 1072.
Since 18 January 2024, applicants in England and Wales no longer complete Schedule IHT421, ‘Probate summary’, to send with the IHT400 — HMRC returns the probate values with the code instead. IHT421 is still used in Northern Ireland. In Scotland, where the grant is confirmation rather than probate, you complete form C1, ‘Inventory’, and HMRC issues a confirmation code.
When it's due: by the end of the sixth month after the month of death. HMRC's notes put the interest rule precisely: “The law says that we must charge interest from the first day of the seventh month after the month in which the person died.” So a death on 7 January means interest from 1 August, and “it does not matter why you've not paid the tax by then”.
Tax, or at least a first instalment, must normally be paid before the grant of probate is issued. This surprises many executors, because the estate's money is often locked away at exactly that point. There are established routes around it:
Our guide to paying inheritance tax before probate walks through each option.
Once HMRC's unique code has arrived:
Next step: apply for probate.
HMRC's own notes flag the parts of the IHT400 where valuation is hard and where it expects a professional to be involved:
Reasonable professional fees for administering the estate are generally payable from the estate rather than your own pocket.
The IHT400 is HMRC's full inheritance tax account. You complete it when the estate of someone who died does not qualify as an 'excepted estate', which is common once the estate is over £325,000 or includes anything complex such as trusts, foreign assets or substantial gifts made in the 7 years before death. It consists of a main form plus supplementary schedules for each type of asset, and it must reach HMRC within 12 months of the death.
You cannot apply until HMRC sends you a unique code. GOV.UK says you will usually get it within 20 working days of HMRC receiving your IHT400 or your inheritance tax payment, whichever is later, but the code — not the 20 days — is what unlocks the application. If 20 working days pass without it, contact the inheritance tax helpline. Since 18 January 2024, applicants in England and Wales no longer send an IHT421 probate summary with the IHT400.
For deaths on or after 1 January 2022, the IHT205 no longer exists. Excepted estates simply report their headline figures within the probate application itself. You only complete the IHT400 if the estate is not an excepted estate. The checker on GOV.UK will tell you which applies.
Only the ones that match what the estate holds. The most common are IHT405 (UK property), IHT406 (bank and building society accounts), IHT407 (household goods and vehicles), IHT403 (gifts in the last 7 years), IHT419 (debts), IHT409 (pensions), IHT410 (life insurance) and IHT435/IHT436 for residence nil-rate band claims. IHT402 transfers unused nil-rate band from a late spouse.
Normally yes. The tax, or at least a first instalment, must be paid before the grant of probate is issued. The Direct Payment Scheme (form IHT423) lets banks pay HMRC directly from the deceased's accounts, and tax on property can be paid in annual instalments, though interest is charged on the outstanding balance.
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