How many forms were updated and why?
April is often the busiest time for content development in the legal tech space, with HMRC releasing form updates in line with minor/major changes to tax rates, reliefs and rules. As such, it is fitting to release the first of our content update summaries. In the future, these updates will be released as part of a monthly/quarterly summary of content additions in the system.
It is important that the latest forms are used when calculating / submitting IHT accounts as outdated forms could lead to issues with calculating the amount of tax due and even delays with IHT clearance. If you are using a software provider to assist with drafting these forms, ensure they provide the latest forms.
A list of the forms that have been updated since 1/1/2026 is below (what has changed on each form is detailed below).
Updated IHT Forms (22)
New IHT437 Form
As you may know, for deaths on and after 6 April 2026, relief at 100% on the
combined value of qualifying agricultural and/or business
property is limited to £2.5 million. This value will include any
gifts of qualifying property made on or after 30 October 2024
and within 7 years of the death and other property (including
trust property) that is treated as part of the estate. Where the
total value of qualifying property exceeds £2.5 million,
the excess will qualify for relief at 50%. To accommodate this, HMRC have introduced a new form to transfer APR / BPR from a pre-deceased spouse - the IHT437. As part of Superlawyer's probate offering, you will be able to complete this form in addition to all the other IHT forms, with helpful, rapid calculations from our groundbreaking data-processing engine.
What has changed on each form?
IHT400 - Complete your Inheritance Tax account - last updated on 6/4/2026
Additional questions collecting information: Deceased's nationality, added IHT437 to schedule checklist, added mention of double taxation convention, added apportionment tool use to checklist
IHT401a - Inheritance Tax: long-term United Kingdom (UK) residence - last updated on 27/2/2026
Added question for double taxation convention
IHT403 - Inheritance Tax: gifts and other transfers of value - last updated on 6/4/2026
Added wording for Agricultural Relief and Business Relief changes
IHT404 - Inheritance Tax: jointly owned assets - last updated on 6/4/2026
Added wording for Agricultural Relief and Business Relief changes
IHT405 - Tell HMRC about houses, land, buildings and interest in land - last updated on 21/4/2026
Changes to questions include: Removal of Fax number question for valuation expert, and additional column on tables, splitting 100% relief and 50% relief in line with the Agricultural Relief and Business Relief changes
IHT412 - Inheritance Tax: unlisted stocks and shares and control holdings - last updated on 6/4/2026
Added wording for Agricultural Relief and Business Relief changes and additional column on tables, splitting 100% relief and 50% relief in line with the Business Relief changes
IHT413 - Inheritance Tax: business and partnership interests and assets - last updated on 6/4/2026
Added wording for Business Relief changes
IHT414 - Inheritance Tax: Agricultural Relief - last updated on 6/4/2026
Added wording for Agricultural Relief changes and increased box sizes so more information can be added if required.
IHT417 - Inheritance Tax: foreign assets - last updated on 11/2/2026
Added question: Are any of the foreign assets distributed under a foreign will?
IHT418 - Tell HMRC about assets held in trust - last updated on 6/4/2026
Added double taxation question and wording for agricultural relief and business relief / rate of relief column.
IHT100a - Tell HMRC about a gift or other transfers of value in a trust - last updated on 6/4/2026
Added wording for Agricultural Relief and Business Relief changes and rate of relief column
IHT100b - Tell HMRC about the end of a qualifying interest in possession - last updated on 17/4/2026
Added wording for Agricultural Relief and Business Relief changes and rate of relief column
IHT100b (death) - Tell HMRC about the end of a qualifying interest in possession because someone has died - last updated on 6/4/2026
Added wording for Agricultural Relief and Business Relief changes and rate of relief column
IHT100c - Tell HMRC about an exit charge on assets in a trust - last updated on 6/4/2026
Added wording for Agricultural Relief and Business Relief changes
IHT100d - Tell HMRC that Inheritance Tax is due on the 10 year anniversary of a trust - last updated on 6/4/2026
Added wording for Agricultural Relief and Business Relief changes and rate of relief column
IHT100e - Tell HMRC about any charges on special trusts - last updated on 6/4/2026
Added wording for Agricultural Relief and Business Relief changes and rate of relief column
IHT100h - Tell HMRC about assets previously held in an '18 to 25' trust - last updated on 6/4/2026
Added wording for Agricultural Relief and Business Relief changes and rate of relief column
D31b - Tell HMRC about a transferor or settlor who is a long-term UK resident, when transitional provisions apply - last updated on 6/4/2026
Additional wording for transitional provisions
D37 - Claim Agricultural Relief on assets held in a trust - last updated on 6/4/2026
Added wording for Agricultural Relief changes and rate of relief column
D38 - Claim Business Relief for assets held in a trust - last updated on 6/4/2026
Added wording for Business Relief changes and rate of relief column
IHT38 - Inheritance Tax: claim for relief — loss on sale of land - last updated on 20/3/2026
Added guidance - include a completion statement with the form for every property that is being claimed for
IHT70 - Inheritance Tax: claim for Inheritance Tax business relief on employee benefit trusts - last updated on 25/2/2026
A new address has been added to form IHT70 for customers to write to.