Open Market Value for Probate — What It Means and Why It Matters
In brief
Open Market Value (OMV) is the price an asset would reasonably fetch if sold on the open market on the date of death. It is the statutory standard for Inheritance Tax under section 160 of the Inheritance Tax Act 1984, based on a hypothetical sale between a willing buyer and a willing seller. OMV is typically lower than insurance replacement value and is the only basis HMRC accepts for probate.
What Is Open Market Value?
Open Market Value (OMV) is the legal standard used to value assets for Inheritance Tax. It represents the price an asset would reasonably fetch if sold on the open market between an unconnected willing buyer and willing seller, with both parties acting prudently and having reasonable knowledge of the relevant facts.
For executors administering an estate, OMV is the only valuation basis HMRC accepts. It is not the price the deceased paid for an item, what insurance values it at, what a family member thinks it is worth, or what a dealer might offer in a quick sale. It is, specifically, the realistic auction or open-market price on the date of death.
Getting OMV right matters financially. Personal possessions valued at insurance figures rather than OMV will typically overstate the estate by 200–300%, leading to overpayment of Inheritance Tax. Items valued too low can trigger HMRC enquiries and personal liability for executors. OMV is the only standard that protects the estate on both sides.
The Statutory Definition: Section 160 IHTA 1984
The legal basis for OMV is section 160 of the Inheritance Tax Act 1984, which provides the foundational rule for all IHT valuations. The full statutory text reads:
"Except as otherwise provided by this Act, the value at any time of any property shall for the purposes of this Act be the price which the property might reasonably be expected to fetch if sold in the open market at that time; but that price shall not be assumed to be reduced on the ground that the whole property is to be placed on the market at one and the same time."
Two principles emerge from this short section. First, the value is what the property "might reasonably be expected to fetch" in an open-market sale — a hypothetical, not an actual, transaction. Second, no discount is permitted on the basis that selling everything at once would depress prices. This is sometimes called the "no flooding" rule, and it prevents executors from claiming a lower value simply because the estate contains a lot of similar items.
The Hypothetical Sale Principle
OMV assumes a hypothetical sale on the date of death. The valuer asks: if this item had been offered for sale in its actual condition, on the actual date of death, in an appropriate open market, what would a willing buyer have paid?
HMRC's Inheritance Tax Manual confirms that costs incurred in making the sale are not deducted from OMV. Auction commission, transport, insurance during transit, and similar selling costs are ignored — the value is the gross sale figure a buyer would pay, not the net figure the seller would receive.
Restrictions that might prevent an actual sale (a leasehold restriction on a property, an export licence on an artwork) do not change the valuation methodology either. The asset is valued under the statutory framework regardless of practical sale impediments, with appropriate market evidence considered for similar restricted assets.
Date of Death — Not Today's Price
OMV is fixed at the date of death. Subsequent price movements — whether the item rises or falls in value before the valuation report is produced — do not change the figure to be reported on the IHT400.
In practice, valuers establish OMV by reviewing comparable sales close to the date of death. For jewellery, watches, art, and antiques, this typically means recent auction results from the months either side of the death. For property, the Valuation Office Agency expects evidence from comparable sales within three to six months of the date of death.
This date-of-death rule has practical consequences. If the deceased held shares that crashed two months after death, the executor still pays IHT based on the higher pre-crash value. Conversely, if a painting dramatically rises in value after death due to a re-attribution, the lower pre-discovery value applies for IHT — although Capital Gains Tax may then apply on subsequent sale.
What Open Market Value Is NOT
Confusion between valuation bases is one of the most common — and costly — mistakes executors make. The table below clarifies what OMV is and is not.
| Valuation Basis | What It Represents | Acceptable for Probate? |
|---|---|---|
| Open Market Value (OMV) | Realistic auction/sale price at date of death | Yes — the only HMRC standard |
| Insurance Replacement Value | Cost to replace with equivalent new item | No — typically 2-3x higher |
| Retail Replacement Value | Current shop price for similar item | No — includes dealer margin |
| Sentimental Value | Personal or family worth | No — irrelevant to HMRC |
| Scrap or Melt Value | Raw material content only | No — ignores maker, age, market |
| Purchase Price | What was originally paid | No — values change over time |
| Probate "Quick Sale" Value | Distressed-sale or trade-buyer offer | No — assumes proper marketing |
How OMV Is Established in Practice
A qualified probate valuer establishes OMV through evidence-based research, not opinion. The methodology combines physical inspection of the item with research into comparable sales.
For chattels — jewellery, watches, art, antiques, classic cars, gold — the gold standard of evidence is recent auction results for comparable items. Major auction databases (LiveAuctioneers, the-saleroom.com, Christie's and Sotheby's archives, specialist house results) provide thousands of sale records that valuers cross-reference against the asset being assessed. Sales after the date of death, particularly those at auction, are explicitly recognised by HMRC as providing "the best evidence of the open market value".
For property, the RICS Red Book methodology requires valuers to identify three to five comparable sales of similar properties, adjust for differences (size, condition, location, date), and arrive at a defensible figure. The Valuation Office Agency reviews property valuations submitted to HMRC and may challenge figures unsupported by comparable evidence.
The result is a written valuation report that documents the items, their condition, the comparable evidence reviewed, and the OMV figure arrived at. This report is enclosed with the IHT400 and forms the executor's defence against any subsequent HMRC enquiry.
Why OMV Matters for Inheritance Tax
OMV directly determines how much Inheritance Tax the estate pays. With IHT charged at 40% above the nil-rate band (currently £325,000, or £500,000 where the residence nil-rate band applies), every £10,000 of correctly assessed value translates to £4,000 of tax.
Overstatement is just as damaging as understatement. Using insurance figures rather than OMV for jewellery and art alone can add tens of thousands of pounds to the estate's IHT bill — money the family never recovers, because reclaiming overpaid IHT after distribution is complex and time-limited.
Conversely, understating OMV exposes the executor personally. HMRC has the power to reopen valuations and impose interest at 7.75% (as of January 2026), plus penalties of up to 100% of the underpaid tax. Executors are personally liable for the shortfall, even after distribution to beneficiaries.
A qualified probate valuer with appropriate professional body membership (NAJ, IRV, RICS, Gem-A or specialist equivalent) provides a defensible OMV figure backed by professional indemnity insurance. The cost is modest, the protection substantial, and the fees are deductible from the estate before IHT is calculated.
Frequently Asked Questions
What is the difference between Open Market Value and market value?
For Inheritance Tax purposes the two are effectively the same — section 160 IHTA 1984 uses the phrase "open market" to define the statutory standard, but valuers and HMRC often shorten this to "market value" in correspondence. The substance is identical: the price the asset would fetch in a hypothetical, unforced, properly marketed sale on the date of death.
Why is Open Market Value used for probate instead of insurance value?
Insurance valuations are designed to reflect the cost of replacing an item with a like-for-like equivalent at retail prices. They typically run 200-300% higher than what the same item would fetch at auction. Using insurance figures for probate would massively overstate the estate and result in overpaying Inheritance Tax. HMRC requires Open Market Value precisely because it represents what the family could realistically realise from selling the asset.
Can the Open Market Value of an item change between the date of death and the valuation report?
No. OMV is fixed at the date of death. Even if the valuer produces the report months later, the figure must reflect what the asset would have fetched on the open market at the date the deceased died. Subsequent market movements are irrelevant to the IHT calculation, although they may matter for Capital Gains Tax on a later sale.
Who is qualified to establish Open Market Value for HMRC?
HMRC does not prescribe specific qualifications, but expects valuations from individuals with demonstrable expertise in the relevant asset type. In practice this means members of recognised professional bodies: NAJ or IRV for jewellery, RICS for property and fine art, Gem-A for gemstones, and specialist auctioneers or valuers for niche categories such as classic cars or wine. Valuers should also carry professional indemnity insurance.