When someone dies and leaves a car as part of their estate, the instinct is often to grab a quick online valuation. It takes seconds and feels like a reasonable starting point.
For probate purposes, it can be a costly mistake.
Why The Price You See Online Is Probably Too High
Online car buying sites like We Buy Any Car are built to generate leads, not to produce defensible valuations. When you type in a registration number and get back a figure in seconds, that number is almost always based on an assumption of perfect or excellent condition. The sites themselves say so, buried in their small print.
This is important because the realistic open market value of most second-hand cars is significantly lower. A missing service history can reduce a car’s value by 15% to 40%, according to guidance published by We Buy Any Car. A missing key can add several hundred pounds to the price. Any bodywork scuffs, worn tyres, or mechanical issues will push it further still.
For probate, the figure that counts is not what a site offers before it has seen the car. It is what the car would realistically have fetched on the open market on the date the person died. Those two numbers can be very different, and if you file your Inheritance Tax return using the higher online estimate, you may end up paying more tax than the estate actually owes.
There are five specific reasons why online valuations fall short for probate, and it is worth understanding each of them.
1. They Assume Perfect Condition (And They Say So)
The major online car buying sites are explicit about this, even if it is easy to miss. Their instant valuations are based on the assumption that the vehicle is in excellent or perfect condition. That is the starting point before anyone has looked at the car, checked its history, or asked a single question about its condition. For a car sitting on a driveway after someone has died, that assumption is rarely accurate, and the gap between “perfect condition” and reality can be substantial.
2. They Cannot Account For What Is Missing
A registration number tells a valuation algorithm very little. It cannot see that the car has one key instead of two, that the service history is incomplete, or that there is a dent on the rear door.
Yet each of these factors reduces what a buyer would realistically pay. Missing service history alone can cut a car’s value by between 15% and 40%. A missing key typically adds a further £250 to £300 in costs that any buyer will factor into their offer. These are not minor adjustments.
3. They Give You Today’s Price, Not The Date Of Death
HMRC requires an open market valuation pinned to the date the person died, not the date you get around to sorting the estate. Online car buying tools are designed to tell you what a car is worth now, and car values move.
A car that was worth £6,000 six months ago may be worth more or less today depending on the market. Using a current consumer quote for a historic valuation date is not just imprecise. It may not be defensible if HMRC asks questions.
4. Asking Prices Are Not Selling Prices
Some executors turn to classified listings such as AutoTrader to find comparable cars and estimate a value that way. It feels logical, but asking prices and selling prices are not the same thing. AutoTrader’s own research found that 70% of buyers would expect a discount of at least 6% if a used car looked scruffy, and only 9% would pay the full asking price for a poorly presented car.
HMRC wants a realistic selling price, not an optimistic listing. There is nearly always a gap between the two.
5. A Weak Valuation Creates Real Legal And Financial Risk
Getting the valuation right can save the estate real money. A car overvalued by £2,000 in a taxable estate means £800 of Inheritance Tax paid unnecessarily.
A proper valuation does not just protect executors from HMRC scrutiny. It makes sure the estate pays exactly what it owes, and not a penny more.
What To Do Instead
Swift Values offers a straightforward alternative. For £25+VAT, a qualified valuer reviews the car using its registration, MOT history, and photographs of the actual vehicle, rather than simply generating a figure from a number plate alone. A professional valuer looks at the evidence, takes condition into account, and produces a valuation that reflects what the car would realistically have fetched on the open market at the date of death.
That is exactly what HMRC expects. The resulting report is compliant with the Inheritance Tax Act and suitable for submission with the IHT400 form, which means executors and solicitors have something defensible in their hands rather than a printout from a car buying website.
For most estates, the car is not the most complex asset to value. But it is one of the easiest to get wrong if you rely on the wrong tools. A valuation from a qualified professional is a small outlay to avoid a much larger problem further down the line.