When you die, the state quietly forgives a tax.
Inheritance tax gets the headlines: 40 percent above the thresholds, charged on everything you leave behind. But there is a second tax that never arrives at all. Every asset you hold that went up in price while you owned it - the house bought decades ago for a fraction of today’s value, the shares held through the good years, the business built from nothing - is revalued on the day you die, and the gain that accrued during your lifetime simply stops existing for tax purposes. Your heirs inherit the asset at its death-day value, as if the gain never happened. Capital gains tax is forgiven at the grave.
The Institute for Fiscal Studies prices that forgiveness at about £1.5 billion a year in revenue the state declines to collect. And here is where the debate gets strange. The people who argue about closing this gap cannot agree on what closing it would even do.
CenTax - Arun Advani, Andrew Lonsdale and Andy Summers - put the yield from a blueprint of capital gains reforms at about £14 billion a year. Read that number carefully. It is the whole package, not the alignment of rates on its own, and alignment is the part that gets quoted.
Rathbones, a wealth manager, runs the arithmetic the other way. Its analysis prices the bill for abolishing the uplift at almost £120,000 on a single inherited home that gained £500,000. That is a figure per estate, not a figure for the Exchequer, and the two are not the same thing.
And the Centre for Policy Studies, the think tank on the other side, says that equalizing capital gains with income tax would cost the Treasury £7.76 billion, and that a 10-point rise on the higher rate would cost £3.6 billion by 2028/29. That last number is not the CPS’s own. It comes from official analysis the CPS is quoting, and HMRC’s own figures show a 1% rise on the lower rate raising £5 million.
The same mechanism is worth £1.5 billion to close, £14 billion to CenTax, and a £7.76 billion loss to the Centre for Policy Studies. Four numbers, one tax, and they do not even agree on the direction.
Let us look at how the uplift works, why it exists, and what each of the proposed fixes would actually do to the same pound of capital.
The Uplift, Explained
Start with the mechanics, because inheritance tax coverage rarely mentions them.
Capital gains tax is a tax on realized gains. You pay it when you sell something for more than you paid for it, and you pay it on the difference between the sale price and your base cost - the price you originally paid. Buy shares at 100, sell at 150, and the 50 is the gain that gets taxed.
When you die, the law does something unusual. It does not tax the gain. Instead it rewrites history: the asset’s base cost becomes its value on the date of death. If your heir sells a year later, the taxable gain is measured from the death-day value, not from what you originally paid. The gain that built up during your lifetime has been rebased away. That is the mechanism, and its technical name is the inheritance tax capital gains uplift.
It is worth being fair about why this exists, because it is not an accident and it is not hidden. Three reasons.
First, inheritance tax is itself the designed charge on wealth at death. The state already takes its bite - 40 percent above the thresholds - from the value of the estate. Capital gains tax is a tax on selling. Death is not a sale. No cash changes hands at the moment of death, and much of what passes is not liquid: a house, a farm, a family firm.
Second, charging a gains bill at the moment of bereavement would force sales at the worst possible moment. A tax on paper gains - gains never realized, never spent - would have to be paid out of the estate, which often means selling the thing itself to pay the tax on its rise in value.
Third, the rebase is administratively sane. It gives the heir a clean record: sell tomorrow and your gain is measured from today. Without it, HMRC and every executor would be tracing purchase prices from decades earlier, through inheritances and gifts, for every asset in every estate.
So the uplift is a real feature of the system, not a loophole in the sense of an oversight. The reason is that the state chooses to tax wealth once at death, through inheritance tax, and to let the capital gains of a lifetime expire with their owner. The IFS figure - about £1.5 billion a year - is the price of that choice.
The proverb “you can’t take it with you” is half true. You cannot take the assets. But neither does the tax on their growth follow you, or your heirs. The gain is the one thing that does not make the journey - and the state waves it through.
The Two Fixes, and the Objection to Both
If the uplift is the problem, there are two ways to remove it, and they are different in a way the headlines rarely say.
The first fix treats death as a disposal event. The law would pretend you sold everything on your last day, compute the accrued gains, and charge capital gains tax on them. The gain does not expire; it is taxed at the gate.
The second fix abolishes the rebase instead. Your heirs would inherit your original base cost along with the asset, so when they eventually sell, the gain they pay tax on would include the gain that accrued while you held it. Nothing is taxed at the moment of death. The charge is simply postponed until the heir sells, and it lands on the full gain of both lifetimes.
Now watch what each fix does to the same pound of capital.
The death-as-disposal version charges the estate twice at the same event. Inheritance tax already takes 40 percent of the value above the thresholds. Adding capital gains tax at the 24 percent higher rate on the same asset at the same event means the gain - the growth you never spent - is taxed once as a gain and again as part of the estate’s value. That is the double-taxation objection, and it is the principal objection to the standalone fix for a reason. Even the Treasury’s own history treats it as a real problem: when the rules have touched this area before, the design has gone out of its way to avoid charging both taxes on the same death.
The no-rebase version avoids the double charge at death but moves the problem sideways. It makes the heir pay tax on gains that accrued before they owned the asset - gains they never realized and never enjoyed - and it defers the bill for years or decades, growing with no interest charged to anyone. The deceased paid nothing. The heir pays for both. The state gets its money eventually, but from the person who inherited the asset, not the person who built the gain.
Neither fix is clean. That is why the debate has produced a third option, and the third option is the most revealing thing in this whole story. We will come back to it.
The Think Tanks Disagree With Each Other
First, the argument. How much money is actually sitting in this mechanism? The adviser layer - the people who model this for a living - has split in public, and the split is not a rounding disagreement.
Rathbones, the wealth manager, prices the abolition of the uplift at £1.5 billion to £2 billion a year. That lands in the same territory as the IFS estimate of what the status quo costs, which is what you would expect from two groups pricing the same mechanism.
CenTax, the tax research group, goes much further. It estimates that fully aligning capital gains rates with income tax rates - the big version of the fix, taxing gains as ordinary income - could raise about £14 billion a year.
And the Centre for Policy Studies, on the other side of the argument, models the opposite sign. A 10-point rise on the higher capital gains rate, it says, would reduce revenue by £3.6 billion by 2028/29. Not raise less than expected. Lose money outright.
So: the same capital, three price tags, two of them pointing in opposite directions. The difference between the CenTax number and the CPS number is not accounting. It is the behavioral response - the assumption about what people do when the tax on selling goes up.
This is the question this site keeps returning to, because it is the question that decides whether a tax rise collects money or destroys it. We dismantled the fantasy that high rates on the rich are free money in The 90% Tax Rate Myth. And we watched the mechanism run live in The Laffer Curve, Alive and Well in Scotland: the Scottish Fiscal Commission’s static estimate for the 48p top rate was £53 million, its dynamic estimate collapsed to £8 million once behavior was included, and the outturn was consistent with the rate actually costing Scotland about £22 million. Same method, three answers - because the only thing that changed between them was the assumption about how people respond.
Capital gains are the most elastic tax base there is, because the taxpayer chooses when to sell. Raise the rate and the response is not mysterious: people sell less, hold longer, die holding, or leave. Every revenue forecast for a gains tax is a bet on that behavior. The CenTax number assumes one set of responses. The CPS number assumes another. The gap between £14 billion raised and £3.6 billion lost is not a technical dispute. It is the whole argument in a spreadsheet.
Note also that if it is too expensive to sell, capital will remain in underperforming assets rather than being realized and reinvested in something with more promise.
The Receipts Tell the Other Half
While the models disagree, the actual receipts are already moving. The state is not starving for capital tax revenue.
Capital gains tax receipts are up 44 percent year on year, at £20.6 billion in total. The January surge tells the story: about £17 billion came in January 2026 against about £10 billion in January 2025 - the self-assessment months, when gains are declared and paid. Capital taxes as a group are the fastest-growing part of the tax system, rising from 1.4 percent to 2.3 percent of GDP by 2030/31, an increase of about 64 percent. The Office for Budget Responsibility projects inheritance tax itself will reach £14.5 billion by 2031, up 67 percent.
Put that next to the £1.5 billion that the uplift is said to cost, and the framing of the debate comes into focus. The slow-motion version of closing the loophole is already happening: rates have been raised, receipts have surged, and the thresholds have been frozen so that more estates fall into the tax every year. The nil rate band has sat at £325,000 since 2009 and is now frozen to April 2031 - seventeen years of inflation doing the raising that no politician ever had to announce. More estates pay, year after year, without a single vote on the principle.
The political argument treats the uplift as untouched money sitting on the table. The fiscal reality is a tax that is already growing faster than any other part of the system. The gap between those two pictures is why the think tanks can disagree so violently: the easy money has largely been collected. What is left is the money that only arrives if you are willing to bet on behavior - or to charge the same capital twice.
The Coupling Fix Is the Tell
Which brings us back to the third option, the one that resolves the double-taxation objection, because it is the option that tells you who actually pays.
The coupling fix works like this. Deny the uplift only where inheritance tax relief applied - where the asset escaped inheritance tax through agricultural property relief or business property relief, the state would still charge the capital gain at death. Where the estate paid full inheritance tax, the rebase would stay. No asset would face both taxes at the same event. Coupled, the fix is defensible: the state forgives one tax or the other, never both, never neither.
Now look at what the state has already done to the reliefs it would be coupling against. Agricultural and business property relief, which once took those assets out of inheritance tax entirely, were cut to 50 percent relief above a combined £2.5 million threshold. Business asset disposal relief - the reduced rate on selling a business - rises from 14 percent to 18 percent from April 2026. The sequence matters: first the reliefs are cut, then the assets inside them are pulled toward the tax, and then the coupling argument - “deny the uplift where relief applied” - arrives to close the remaining gap. The farm and the family firm sit at the center of every step - and they are the group inheritance tax reform falls hardest on.
The tell is that the standalone fix is indefensible and everyone modeling it knows it. Charge inheritance tax at 40 percent and capital gains tax at 24 percent on the same asset at the same event, and the proposal dies in public on the double-taxation objection within a week. So the realistic version of closing the uplift is the coupled version. And the coupled version denies the uplift in exactly the places where the reliefs were already cut - the assets the state has already decided to reach for.
Who Pays for the Second Bite
Step back and the shape is familiar.
The estates that would pay are the ones holding assets with large unrealized gains: the house bought decades ago, the business held across a working life, the shares never sold because selling was never the plan, as Warren Buffett suggests. These are not the estates the “tax the rich” slogan pictures. They are the diffuse, politically weak group we met in The Pension Tax Raid - the group that has no lobby, no campaign, and no spokesperson, the one that discovers the new rule when the letter arrives. The demand always names the very rich. The supply is whoever holds an appreciating asset and dies.
The same question applies at every step: who actually pays? The person the headline pictures, or the person the mechanism reaches? A tax on death is paid by the dead in name and by the living in fact - the heir who sells the house to pay the bill, the family that gives up the business. The second bite at capital is never taken from the person who built the capital. It is taken from the people who inherit it, in cash, at often the worst moment of their lives. The state can collect the same £14 billion or lose the same £3.6 billion depending on which behavior it assumes - but either way, the group that finances the experiment is the one with the least voice in it.
The Conclusion
Next time someone says “close the loophole,” ask which fix they mean. The one that taxes the same money twice - the death-as-disposal version that stacks capital gains tax on top of inheritance tax at the same event? The one that taxes the heir later - the no-rebase version that makes the next generation pay for gains they never enjoyed? Or the one the think tanks say loses revenue - the rate rise that models show costing the Treasury money by the end of the decade?
The uplift is real, and £1.5 billion a year is a real price for it. But “close the loophole” always sounds free, and it never is. The mechanism forgives the gain; the fixes do not forgive anything - they just decide who pays for it, and when, and how many times the same pound of capital gets taxed along the way. The loophole is worth £1.5 billion to close and £3.6 billion to tax harder, and the difference between those two numbers is not a disagreement about arithmetic. It is a disagreement about what people do when the state reaches for their capital - and that is a bet, not a forecast.