Claim Unused Allowance for Agricultural or Business Property Relief (IHT437)
Summary
HMRC has published form IHT437 (effective 8 April 2026) enabling executors and personal representatives to claim and transfer unused 100% agricultural or business property relief allowances from a deceased spouse or civil partner to the current estate. The form must be submitted alongside form IHT400 for inheritance tax purposes.
What changed
HMRC has released form IHT437 enabling the transfer of unused 100% agricultural or business property relief allowances between spouses or civil partners for inheritance tax purposes. The form is used alongside IHT400 to claim the transferred relief allowance from a previously deceased partner.
Estate executors and personal representatives dealing with agricultural property, business assets, or mixed estates should use this form to reduce inheritance tax liability. Users must gather all required information before starting as partial forms cannot be saved. The form applies specifically to transfers between spouses and civil partners, not to other beneficiary transfers.
What to do next
- Complete IHT437 form in full before printing
- Submit IHT437 with form IHT400 to HMRC probate address
- Ensure web browser is updated before accessing form
Archived snapshot
Apr 9, 2026GovPing captured this document from the original source. If the source has since changed or been removed, this is the text as it existed at that time.
Form
Claim unused allowance for agricultural property or business property relief (IHT437)
Use form IHT437 to claim and transfer any unused relief allowance for agricultural or business property to the deceased’s estate.
From: HM Revenue & Customs Published 8 April 2026 Get emails about this page
Documents
Claim to transfer unused relief allowance for agricultural property or business property (IHT437)
Ref: IHT437
PDF, 1.33 MB, 3 pages
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Details
Use the IHT437 with form IHT400 to transfer any of the unused 100% relief allowance from the previously deceased spouse or civil partner, to the deceased’s estate.
Before you start filling in the form
Make sure your web browser is up to date.
You’ll need to fill in the form fully before you can print it. You cannot save a partly completed form so make sure have all the information you need before you start to fill it in.
Where to send the form
After you’ve filled in the form, send it to the postal address given at Inheritance Tax: general enquiries.
Related guidance
Find out:
- how to work out Agricultural Relief for Inheritance Tax
- what qualifies for Business Relief for Inheritance Tax
Published 8 April 2026 Get emails about this page Print this page
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