United KingdomChartered Institute of Taxation
HMRC urges full IHT400 where estate values or allowances are uncertain
An educational letter targets agents who filed estates as excepted near nil-rate-band thresholds, with a focus on valuations and the different inheritance-tax allowances.
By Taxxa AI OyPublished 14 August 2026
HMRC is advising agents to submit a full IHT400 where there is uncertainty about estate valuations or entitlement to allowancesTAX. The educational letter is aimed at agents who submitted estates as excepted where values are close to nil-rate-band thresholds
TAX and may indicate that a full IHT400 is required.
In information supplied to CIOT, HMRC said it planned to issue the letters on 27 July 2026TAX. The letter aims to improve understanding of the Nil Rate Band (NRB), Transferable Nil Rate Band (TNRB), Residence Nil Rate Band (RNRB) and Transferable Residence Nil Rate Band (TRNRB). It encourages accurate valuations and allowances when applying for probate. According to the information provided to CIOT, the letter also directs recipients to GOV.UK guidance and provides contact details for agents wishing to discuss it.
The filing distinction matters even where an estate may ultimately have no inheritance tax to pay. HMRC’s excepted-estates manual explains that the exemption from delivering an account depends on meeting the relevant conditions. For deaths on or after 1 January 2022, the excepted-estate procedure involves declaring that the estate is exceptedGOV, confirming whether transferable nil rate band is claimed
GOV and providing three inheritance-tax values on the Probate or Confirmation forms
GOV.
Residence nil rate band has its own claim procedure. HMRC’s guidance tells claimants to provide the amount claimed and supporting information on the IHT400 account and IHT435. It also explains that the allowance includes any unused residence nil rate band transferred from a spouse or civil partnerGOV. The educational campaign expressly covers both the residence allowance and its transferable counterpart.
Timing can also change the filing route for transferable nil rate band. HMRC’s manual requires the relevant forms to reach the Probate Registry or Sheriff Court within 24 months after the end of the month of death. Personal representatives cannot apply for a grant as an excepted estate outside that limit where a late transferable-band claim is neededGOV: a late claim is at an HMRC officer’s discretion and must be made using IHT400 and the appropriate supplementary pages
GOV.
The underlying account exemption is in the Inheritance Tax (Delivery of Accounts) (Excepted Estates) Regulations 2004, as amendedGOV, explained in HMRC’s excepted-estates guidance.
Review excepted-estate filings near nil-rate-band thresholds and submit IHT400 where valuations or allowance entitlement are uncertain, checking the required claim forms and time limits.