Swift Values Probate Valuation Survey:

Key Findings

81% Of Families Risk Overpaying Inheritance Tax

Most families want to get probate right, but our latest research shows just how easy it is to make a simple mistake that quietly increases the inheritance tax bill. When we asked people to estimate the probate value of everyday household items, the vast majority significantly overvalued them.

And because HMRC calculates inheritance tax from these figures, overvaluation — even by accident — means estates can end up paying more tax than they need to.

In this report, we break down what people got wrong, why it happens, and what it means for executors trying to follow the rules. The findings show that saving on inheritance tax is often far simpler than people realise: it starts with getting probate values right.

About the Survey

To understand how well people judge probate values, we ran a short national survey using five everyday household items: a six-month-old John Lewis sofa, a Bosch washing machine, an Apple iPad Pro, a Georgian longcase clock, and a 0.7ct diamond ring.

We chose these because they reflect the mix of belongings found in most homes across Britain — from basic white goods to modern consumer tech, typical mid-market furniture, inherited antiques, and high-ticket jewellery. The aim wasn’t to capture every type of item, but to provide a quick, practical snapshot of how people think about value in a probate context.

Participants were simply asked to estimate each item’s probate value — that is, its likely open-market resale value at the date of death — and their answers were compared with professional valuations. The results revealed a clear pattern: across all categories, the majority of people overestimated.

How Probate Valuation Mistakes Drive Up Inheritance Tax

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Across all five items, over 80% of people overestimated probate values, meaning the vast majority would unintentionally report inflated figures — and risk overpaying inheritance tax as a result.

Category: Soft Furnishings

Item: A John Lewis “Camber” medium 2-seater sofa, bought new for £976.65, 6 months old and in excellent condition. Original RRP £976

Data Snapshot
Original price: £976
Probate value: £100 (verified auction result here)
Correct valuation rate: 7.6%

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Why Soft Furnishings Are Commonly Overvalued For Probate

Sofas feel expensive because they were expensive — they’re a considered purchase, often bought new, often bought on finance, and usually one of the larger items in a home. But probate valuation isn’t based on retail price, condition, or sentiment. It’s based on what the item would realistically sell for on the open market, which in practice usually means public auction or second-hand resale.

Why the Probate Value Is So Low For Sofas

Very few people ever buy a second-hand sofa from auction — and that’s exactly the point. Once a sofa leaves a showroom, the market for it shrinks dramatically.

Second-hand buyers have to factor in the cost and hassle of delivery, the limited pool of people happy to buy used soft furnishings, and the fact that almost all major retailers offer fast, cheap finance on brand-new furniture. All of that pushes real resale values down — far more than most people expect.

This is why probate valuations for sofas, beds and general furnishings are typically modest, even when the item is nearly new. They may take up a lot of space in a home, but they rarely carry equivalent value in a probate context.

A nearly-new John Lewis sofa feels valuable, yet for probate it’s worth around £100. Only 7.6% of participants selected the correct bracket, with most adding hundreds to its value.

“More than 90% of people overvalued the sofa, showing just how easy it is to mistake retail price for probate value — and how quickly an honest estimate can turn into an inflated inheritance tax bill.”

Category: Antiques

Item: A Georgian walnut-cased longcase clock by John Stancliffe, eight-day movement, moonphase, subsidiary seconds, and date aperture. Genuine antique in working order.

Data Snapshot
Typical historic purchase price: Often £2,000–£3,000+ in the 1980s–1990s
Probate value: £320 (verified auction result here)
Correct valuation rate: 5.2%

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Why Antiques Are Commonly Overvalued For Probate

Antiques often come with a story — they’ve been in the family for generations, they were expensive when purchased, or they were regarded as heirloom pieces. But probate valuation isn’t about age, rarity, or sentiment; it’s about what the item would actually sell for today on the open market.

Longcase clocks are a perfect example. They were hugely popular between the 1960s and 1990s, regularly fetching thousands at auction. Many families still assume those values hold. But the market has shifted dramatically.

Why the Probate Value Is So Low

The reality is that demand for longcase clocks has collapsed. Modern homes are smaller, interior styles have changed, and very few people under 50 are looking to introduce a 7-foot clock into their living room. If you ask yourself how many of your friends or family actively want to buy one, the answer highlights exactly why values have dropped.

Buyers are now far more interested in mid-century pieces — G Plan, Ercol, Danish teak — than traditional Georgian or Victorian furniture. As demand has fallen, auction prices have followed.

This gap between perceived value (“it must be worth a lot, it’s an antique”) and probate value is one of the biggest causes of overvaluation. Executors often presume age equals worth, but in today’s market, that simply isn’t the case.

Swift-values-Longcase-Antiques-Valuation

“Only 5% valued the clock correctly, proving that antiques are one of the most commonly overestimated categories — and a major source of accidental overpayment to HMRC.”

Category: Jewellery

Item: A 0.7ct platinum solitaire diamond ring, GIA-certified, purchased new in 2020 for £6,250. In excellent condition.
Probate value: £1,250 (based on assessment by an FGA/DGA-qualified gemologist)

Data Snapshot
Retail price paid: £6,250
Probate value: £1,250
Correct valuation rate: 9.6%

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Why Diamond Rings Are Commonly Overvalued For Probate

Jewellery carries two powerful distortions: sentiment and retail pricing.

Families often associate a ring with emotional significance — an engagement, milestone, inheritance — and that sentiment naturally colours the perceived value. But probate valuation cannot account for emotion; HMRC only cares about what the piece would sell for on the open market.

The second distortion is retail markup. High-street jewellers sit in prime locations, hold millions of pounds in stock, and carry substantial insurance and staffing costs. Naturally, their margins are significant. As a result, the price paid in a jewellery shop rarely reflects what the same piece would achieve at auction or through trade buyers.

Most people guessed several thousand, but for probate this ring is worth just £1,250.

Why the Probate Value Is So Low

Diamond rings are actually one of the easiest categories to value for probate because the industry publishes daily pricing data for stone size, cut, colour and clarity — and trained gemologists (FGA/DGA) work with this every day.

In this case, the ring was valued at £1,250 for probate, partly because it carried a GIA certificate, which helps underpin confidence in the grading. However, even that figure is generous. At many regional auction houses, a 0.7ct diamond ring of similar quality could realistically achieve £700–£1,000 at hammer.

That’s the crucial point:
Retails shops sell new jewellery at high margins; auction houses sell second-hand jewellery at market value.
Probate must reflect the latter.

This gap between retail price and resale value is why jewellery is consistently one of the most overvalued categories in probate — and one of the easiest places where estates unintentionally pay too much inheritance tax.

“Over 90% of respondents overvalued the ring, highlighting how sentiment and retail pricing regularly lead families to submit inflated figures and pay more inheritance tax than necessary.”

Category: Consumer Electronics

Item: Apple iPad Pro 12.9-inch (4th generation, 2020), Wi-Fi + Cellular, with original box. Original RRP £1,119.

Data Snapshot
Original retail price: £1,119
Probate value: £220 (based on this verified auction result)
Valuation accuracy: 28.7% (the highest of all items in the survey)

Why Tech Is Valued More Accurately For Probate

Compared with jewellery and antiques, respondents performed noticeably better on the iPad. That’s likely because people have a clearer mental model for tech depreciation — most of us regularly replace phones, tablets, or laptops and understand that they lose value quickly.

This familiarity makes it easier for people to give estimates closer to the true probate value.

Why the Probate Value Is So Low

For probate, we use actual physical auction results, not eBay prices. And the distinction matters:

Auction buyers bid “as seen” with no warranty
There is no guarantee of battery condition, remaining lifespan, or hidden faults
Buyers must often collect the item with no shipping available
There is more risk than buying from a trade seller on eBay who offers returns, warranties, or refurbished guarantees

Because of this added uncertainty, auction prices for second-hand electronics tend to be significantly lower than retail, or even lower than typical eBay “Buy It Now” listings.

The verified auction result for this iPad was £220 — a realistic reflection of what HMRC expects for probate. Even in excellent condition and with its original box, a four- or five-year-old iPad simply doesn’t command high resale values at physical auction.

This is why consumer tech, despite feeling expensive at purchase, almost always shows substantial depreciation in probate valuations.

Tech depreciates quickly, and the iPad Pro in the study has a probate value of around £300–£350. Even so, more than two-thirds of people still overestimated it.

“Even with tech, where people expect depreciation, more than 70% still overestimated the probate value — a reminder that everyday items can quietly push up the tax bill when guessed incorrectly.”

Category: White Goods

Item: Bosch Maxx 6 washing machine, circa 2012, in working condition.

Data Snapshot
Typical replacement cost when new: £250–£400
Probate value: £40 (based on this verified auction result)
Valuation accuracy: 43.4% (the highest accuracy of all items)

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Why White Goods Are Often Valued More Accurately For Probate

White goods tend to be the most intuitive category for people. Unlike antiques or jewellery, most families understand that appliances lose value quickly, and that a 10–12-year-old washing machine is unlikely to be worth very much.

That familiarity shows in the data: this item had the highest valuation accuracy of the entire survey.

Why the Probate Value Is So Low

In most homes, appliances like washing machines, tumble dryers and fridges are bought, used heavily, and then replaced at the end of their life. They aren’t regularly bought and sold second-hand, and they have almost no collector or resale market.

Older appliances also carry risks for buyers — unknown lifespan, mechanical wear, and transport/delivery costs — all of which keep second-hand prices extremely modest. At physical auction, a working washing machine of this age regularly sells for £20–£40, which is why the probate value reflects that figure.

In practical terms, white goods make up a large percentage of a home’s contents but very little of its probate value. They’re functional assets, not appreciating ones — and probate valuation follows the market, not the original cost.

A standard Bosch washing machine has a probate value of roughly £40

“Almost 60% overvalued the washing machine, showing that even low-value items can be misreported — and those small errors add up when HMRC applies 40% inheritance tax.”

Does Age Matter?

Our data shows that age has some effect on accuracy — but not in the way many would expect. Participants aged 55–64 were the most accurate, valuing around 26% of items correctly, while younger groups, particularly those aged 25–34, averaged closer to 14%.

However, even the most accurate age group still got three out of four valuations wrong. And crucially, having acted as an executor before did not improve results. People with previous probate experience performed no better than those doing it for the first time.

In other words:
Age provides a slight advantage, but not enough to reliably value an estate. Most people — regardless of experience — still overestimate.

That finding reinforces the central risk highlighted throughout this report: probate valuation mistakes aren’t limited to any particular generation. They happen everywhere, and they’re easy to make.

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The Cost of Getting It Wrong

Probate valuation errors don’t just distort the numbers — they directly inflate inheritance tax. To illustrate the point, we looked at the most common incorrect value brackets chosen in our survey and compared them against the correct probate values. Using HMRC’s 40% tax rate, we can estimate the potential overpayment.

Below is a clear, illustrative model showing how much extra tax an estate would pay if an executor submitted the most typical incorrect valuation for each item.