Form IHT400: the Inheritance Tax account, and how to fill it in
This page covers when form IHT400 is needed, what it asks for, its schedules and the deadlines.
What is form IHT400?
Form IHT400 is the return HMRC calls the Inheritance Tax account. GOV.UK publishes it as Inheritance Tax account (IHT400), last updated 22 May 2026.
You use form IHT400 to apply for probate, or confirmation in Scotland, when the estate is not excepted or there is tax to pay.
HMRC's companion guide is "Guide to completing your Inheritance Tax account (IHT400 notes 2022)", the IHT400 notes people search for. If you are still working out which papers the estate needs, start with inheritance tax forms.
Do I need to complete form IHT400?
You need form IHT400 if the estate is not an excepted estate. GOV.UK's guidance on checking the type of estate says an estate is usually excepted if:
Below the threshold: the estate is worth less than the current Inheritance Tax threshold.
Transferred threshold: the estate is worth £650,000 or less and unused threshold is transferred from a spouse or civil partner who died first.
Spouse or charity: everything was left to a spouse or civil partner living in the UK, or to a qualifying charity, and the estate is under £3 million.
Foreign domiciliary: the person lived permanently outside the UK and their UK assets are worth £150,000 or less.
Some estates must send full details even when no tax is due: where the person gave away more than £250,000 in the 7 years before they died, left an estate worth more than £3 million, or held foreign assets worth more than £100,000. Gifts are easy to miss, so check the 7 year rule for inheritance tax.
As of August 2026 the nil rate band is £325,000. See the inheritance tax threshold.
For deaths between 6 April 2011 and 31 December 2021, excepted estates used form IHT205, which GOV.UK still lists as current for that window.
What information does form IHT400 ask for?
Form IHT400 asks for a complete picture of the estate at the date of death: the assets owned, the debts owed, the gifts made, the reliefs and exemptions claimed, and the tax calculation.
It also asks whether you want to pay in yearly instalments. You must say so on form IHT400 itself.
Form IHT400 is interactive and needs Adobe Reader. You cannot save a partly completed form IHT400, so gather every valuation and balance before you start, using how to value an estate for probate. No box numbers appear on this page, because HMRC renumbers them between versions.
Which schedules go with form IHT400?
Form IHT400 is a shell. The detail goes on supplementary schedules numbered IHT401 to IHT437, and you send only the ones that apply.
Assets: IHT405 (houses, land and buildings), IHT406 (bank and building society accounts), IHT407 (household and personal goods), IHT411 (listed stocks and shares), IHT417 (foreign assets).
Gifts and joint assets: IHT403 (gifts and transfers of value), IHT404 (jointly owned assets).
Debts: IHT419 (debts owed by the deceased).
Reliefs: IHT402 (unused nil rate band), IHT435 (residence nil rate band), IHT436 (transferable residence nil rate band), IHT437 (agricultural or business property relief).
Three forms sit alongside: IHT421 (probate summary), IHT422 (Inheritance Tax reference) and IHT423 (Direct Payment Scheme).
When do you need to send form IHT400, and what happens next?
Form IHT400 must be sent within 12 months of the person dying, and before you apply for probate.
Inheritance Tax must be paid by the end of the sixth month after the death. GOV.UK's example: if the person died in January, you must pay by 31 July. HMRC charges interest if you pay late.
If there is tax to pay, apply first for an Inheritance Tax reference (IHT422), last updated 5 June 2026. You need that reference before you send form IHT400.
After you send the forms, HMRC sends a unique code, and you need that code before you can apply for probate. GOV.UK does not publish a turnaround time for this, so build in some slack rather than timing your probate application to the day. Once the code arrives, how to apply for probate covers the rest.
One notification, not forty
Deciding whether an estate needs form IHT400 means knowing what the person actually held, which usually means chasing banks, pensions, insurers and utilities one at a time. Legacy Trail finds the accounts and services the person held and notifies them centrally.
Frequently asked questions
Form IHT400 is published on GOV.UK as Inheritance Tax account (IHT400), last updated 22 May 2026. The same page carries the IHT400 notes, the guide to completing the account. The form is interactive and needs Adobe Reader, so open it in Reader rather than a browser preview.
HMRC sends a unique code once the Inheritance Tax forms have been received. You need that code before you can apply for probate, and the application cannot proceed without it. Keep the code with the estate papers, because the probate service asks for it.
Yes. Form IHT400 is used to apply for probate or, in Scotland, confirmation, where there is Inheritance Tax to pay or the estate is not excepted. Inheritance Tax rules run UK wide, so the same 12 month filing deadline and sixth month payment deadline apply. In Scotland you also fill in form C1, 'Inventory', which the Sheriff's Court needs before it can issue confirmation (GOV.UK).
Nothing replaced it. For deaths on or after 1 January 2022 there is no excepted estate form. You check whether you need to send full details of the estate, and if it is excepted you declare the values as part of the probate application.
This article is for general information only and does not constitute legal advice. Individual circumstances vary. If you are dealing with an estate, consider taking advice from a solicitor who specialises in probate. For other guidance specific to your circumstances, speak to a funeral director, Citizens Advice, or a regulated financial adviser.