Inheritance Tax Valuation Dispute UK (2026): How HMRC Challenges Estate Valuations and How to Respond

HMRC opens a formal enquiry when it believes the value of an asset in the IHT400 return is too low. This is one of the most common sources of additional IHT liability after a grant of probate: (1) WHAT HMRC CHECKS: HMRC's Inheritance Tax technical team reviews every IHT400. Key red flags include: (a) property valued significantly below comparable sales in the same area; (b) unquoted share or business asset values that appear inconsistent with trading performance; (c) open market value stated as 'nil' or negligible for assets that clearly have value; (d) related party transactions (e.g. the executors sell the asset to a family member at a discount); (e) omission of assets that HMRC's records show should exist (e.g. property appearing on Land Registry, shares shown in Companies House filings); (2) THE ENQUIRY POWERS — IHTA 1984 s.219: HMRC has wide powers to require information from personal representatives and their advisers. Under s.219, HMRC can require the executor to: (a) produce documents relating to the estate; (b) provide written accounts of assets and their values; (c) deliver valuations, contracts, and related paperwork. Failure to comply with a s.219 notice can result in penalties; (3) HOW HMRC COMMENCES A VALUATION ENQUIRY: for property: HMRC's District Valuer Service (DVS) is instructed to conduct a desktop review and, if the property warrants it, a physical inspection and valuation. DVS reports are confidential (the executor does not receive them automatically) but their findings are communicated to the executor as HMRC's revised position. For shares: HMRC's Shares and Assets Valuation (SAV) team deals with unquoted shares, interests in partnerships, and other non-listed securities. SAV applies a different methodology to the executor's valuation and requests trading accounts, management accounts, and dividend history from the company; (4) TIMING: HMRC typically has a period of: (a) 4 years from the date the IHT account was accepted to raise an assessment for a 'careless' underpayment; (b) 20 years for deliberate underpayment or fraud. Most valuations challenges arise within 1-2 years of the account being filed. Executors should not distribute the estate until any HMRC enquiry is resolved, or obtain clearance under IHTA 1984 s.239.

The District Valuer Service (DVS) is the government's property valuation authority, operating within the Valuation Office Agency (VOA). DVS acts as HMRC's expert valuer for IHT purposes: (1) HOW DVS APPROACHES THE VALUATION: DVS uses comparable sales evidence to assess the open market value of the property at the date of death (IHTA 1984 s.160). Key principles: (a) open market value = the price which the property might reasonably be expected to fetch if sold in the open market at the date of death (between a willing buyer and a willing seller, in an arm's length transaction); (b) actual sale prices after death are relevant evidence (especially for sale within 12 months — see IHT35 below) but not determinative; (c) DVS may visit the property or conduct a desktop review depending on the value and circumstances; (d) DVS looks at comparable sales within the same street, postcode, or area; asks about the property's condition at the date of death; and considers planning permissions or development potential; (2) WHAT EXECUTORS SHOULD DO WHEN DVS CONTACTS THEM: (a) engage promptly — do not ignore DVS correspondence; (b) provide a written submission supporting the original valuation with comparable evidence; (c) consider commissioning a Red Book valuation from an RICS-registered valuer (a RICS Red Book valuation, conducted under RICS Valuation — Global Standards 2022, carries professional weight and is the strongest rebuttal evidence against DVS); (d) provide evidence of the property's condition at the date of death (survey reports; photographs taken around that date; maintenance records); (3) NEGOTIATION WITH DVS: most IHT property valuation disputes are resolved by negotiation without going to tribunal. Executors or their advisers submit evidence; DVS or HMRC revise their position; a compromise figure is agreed. The negotiated value is then used to calculate any additional IHT due (plus interest from the original due date); (4) LOSS ON SALE RELIEF — IHT35: if the property is sold within 4 years of the date of death for less than the IHT value, executors can claim loss on sale relief under s.191-198 IHTA 1984 (using form IHT35). This reduces the IHT value to the actual sale price and generates a refund of overpaid IHT. This relief is particularly valuable when property markets fall after the death.

The Shares and Assets Valuation (SAV) team deals with: unquoted trading company shares; investment company shares; partnership interests; certain business assets. SAV challenges can result in very significant additional IHT: (1) HOW UNQUOTED SHARES ARE VALUED FOR IHT: the open market value of unquoted shares at the date of death is a matter of expert judgment. Common methodologies include: (a) earnings-based valuation: a multiple of maintainable earnings (typically based on comparable quoted companies in the same sector, discounted for the private company illiquidity and minority interest, if applicable); (b) net assets valuation: total assets minus liabilities; appropriate for holding companies, investment companies, or asset-rich businesses; (c) dividend yield basis: relevant for minority shareholdings in profitable companies that pay regular dividends; (d) combination approach: SAV often applies multiple approaches and arrives at a weighted average; (2) WHAT SAV REQUESTS: on opening an enquiry, SAV will request: (a) the company's audited accounts for the last 3-5 years; (b) management accounts to the date of death; (c) evidence of any recent arm's length share transactions in the company; (d) information about the company's business, assets, order book, and prospects at the date of death; (e) shareholder agreements and articles of association; (3) THE IMPACT OF BUSINESS PROPERTY RELIEF (BPR): where Business Property Relief (100% or 50%) is claimed on the shares, the valuation dispute affects the IHT calculation only to the extent of the non-BPR element. However, SAV also checks the BPR claim itself — if HMRC challenges the availability of BPR on the shares (e.g. because the company holds too many investment assets — IHTA 1984 s.105(3)), the valuation becomes critical; (4) NEGOTIATION WITH SAV: executors' advisers (typically a firm's corporate finance or tax valuation team) engage with SAV to debate the appropriate methodology and inputs. SAV will consider professional counter-reports. The process typically takes 6-18 months for complex estates; (5) APPEAL: if agreement cannot be reached, a Notice of Determination under s.221 and then an appeal to the First-tier Tribunal under s.222 is the route.

If HMRC and the executor cannot agree a valuation through negotiation, HMRC issues a formal Notice of Determination (also called a 'determination') under IHTA 1984 s.221 and the appeal process begins: (1) THE NOTICE OF DETERMINATION — IHTA 1984 s.221: a Notice of Determination is HMRC's formal statement of the IHT value it has determined for the disputed asset. It is the starting point for the formal appeal process. The notice sets out the value HMRC has determined, the tax due on that basis, and the right to appeal; (2) NOTICE OF APPEAL — IHTA 1984 s.222: within 30 days of the Notice of Determination, the executor (or other affected person) must lodge a Notice of Appeal to preserve the right to challenge. Failure to appeal within 30 days results in the determination becoming final and binding. The Notice of Appeal must: (a) identify the determination being appealed; (b) state the grounds of appeal; (c) state the alternative value the appellant contends is correct; (3) ALTERNATIVE DISPUTE RESOLUTION (ADR): before going to tribunal, HMRC offers ADR (mediation with an independent HMRC mediator). ADR is free, voluntary, and without prejudice. Many valuation disputes settle at ADR stage; (4) FIRST-TIER TRIBUNAL (TAX CHAMBER): the First-tier Tribunal (FTT) is an independent judicial body. Valuation appeals are heard by the Tax Chamber (Property Branch for land valuation; Tax Branch for shares and other assets). The FTT has power to determine the value of the asset itself — it is not limited to reviewing HMRC's determination for legal error. Each party calls expert evidence (typically an RICS-registered valuer for property; an independent business valuer or corporate finance expert for shares). The FTT judge and, in technical cases, a specialist member, assess the competing expert evidence; (5) COSTS IN THE FIRST-TIER TRIBUNAL: the FTT normally makes no order for costs (each party bears its own costs). However, if a party acts unreasonably in the proceedings, the tribunal can award costs against them. Professional fees for a disputed valuation hearing in the FTT can exceed £30,000-£100,000 each side — making negotiated settlement highly attractive; (6) UPPER TRIBUNAL: appeals on points of law from the FTT lie to the Upper Tribunal (Tax and Chancery Chamber) and ultimately to the Court of Appeal.

The best way to avoid a prolonged HMRC valuation dispute is to prepare robust valuations from the outset: (1) PROPERTY VALUATIONS — USE RICS RED BOOK: the strongest protection against DVS challenge is an RICS Red Book valuation (compliant with RICS Valuation — Global Standards 2022; formerly 'Red Book'). This is a formal written valuation by an RICS Registered Valuer (MRICS or FRICS) conducted in accordance with the Royal Institution of Chartered Surveyors standards. Key features: (a) the valuer visits the property and assesses its condition as at the date of death; (b) the report states the Market Value (MV) opinion with a date of valuation matching the date of death; (c) the report includes comparable evidence; (d) the valuer takes professional responsibility for their opinion. A Red Book valuation carries significantly more weight with DVS than a 'probate valuation' from an estate agent; (2) SHARES — INSTRUCT A SPECIALIST: for unquoted shares, instruct a specialist business valuation firm (one whose valuer has experience in SAV disputes and IHT valuation). The valuation should follow established IHT valuation methodology and be accompanied by supporting analysis; (3) DATE OF DEATH VALUES: all valuations must be as at the date of death, not the date of instruction or the date of the valuation report. Evidence of the property or business's condition at the date of death is critical; (4) DOCUMENT EVERYTHING: keep contemporaneous evidence of the condition, use, and state of assets at the date of death: photographs; condition survey reports; management accounts as close to the date of death as possible; (5) CONSIDER GROSSING UP: where the estate pays IHT on assets that are valued net of any incumbrance (e.g. a property subject to a mortgage), the IHT liability affects the net value — ensure valuations are correctly grossed up or netted down as appropriate; (6) BUSINESS PROPERTY RELIEF — CHECK CAREFULLY: before filing IHT400, check BPR eligibility carefully. A claim for 100% BPR on shares that HMRC then challenges (arguing the company holds too many investment assets) turns a nil IHT bill into a large one. HMRC has focused particularly on 'excepted assets' (s.112) and 'mainly' investment activity (s.105(3)) in recent years; (7) IHT35 AND IHT38 CLAIMS: keep options open for post-death relief claims: IHT35 (loss on sale of land within 4 years); IHT38 (loss on sale of quoted shares within 12 months of death). Both reduce the IHT value to the actual sale proceeds.