The Office for Budget Responsibility now projects that inheritance tax receipts will rise from £9 billion this year to £15 billion by 2030/31, with reforms announced in the October 2024 Autumn Budget driving a growing share of that total. The forecast means a significantly larger number of estates passing through probate will face an IHT liability over the next five years.
The OBR published its updated Economic and Fiscal Forecast alongside Chancellor Rachel Reeves’s Spring Statement on 3 March 2026. The Chancellor did not announce new tax policies, but the OBR’s projections laid bare the long-term impact of changes already set in motion.
Two major reforms are doing the heavy lifting. From April 2027, inherited pension pots will be included in the value of an estate for IHT purposes. Alongside this, caps on agricultural property relief and business property relief will bring more farming and business estates into the tax net.
Together, these measures will account for 14% of all IHT revenue by the end of the 2030/31 financial year.
In the near term, IHT receipts for 2025/26 are forecast at £9 billion, a 4.6% increase on the previous year. The OBR said baseline receipts are running around £300 million a year higher than it predicted in November, largely because of rising equity prices.
A late-2025 policy change did soften the picture slightly. The government increased the threshold for 100% agricultural and business property relief from £1 million to £2.5 million, effective April 2026. The OBR estimates this will reduce receipts by around £100 million in the medium term.
Three factors are pushing more estates above the IHT threshold: rising house prices, rising equity values, and the cumulative effect of the Autumn Budget policies. The OBR said a growing proportion of deaths will now trigger an IHT charge, pulling more families into the system.
For anyone currently acting as an executor or administrator of an estate, these forecasts are a signal that IHT is becoming harder to avoid. If the person who died held a pension pot, owned a farm, or ran a business, the rules governing what counts towards the taxable estate are changing. Executors should check whether the estate could be affected by the incoming pension and relief changes and seek professional advice early, particularly where valuations of property, land, or business assets are needed.
The OBR was candid about the limits of its projections. Its official forecast document stated: “The behavioural responses to these measures and the tax base for inheritable pension wealth are particularly uncertain, adding further uncertainty to the forecast.”
The broader picture shows the government leaning more heavily on capital taxes overall. The OBR predicts capital taxes, which include IHT, capital gains tax, and property transaction taxes, will rise from 1.4% of GDP in 2024/25 to 2.3% in 2025/26. Policy measures introduced since autumn 2025 are expected to raise an extra £6 billion a year in capital taxes by the end of the decade.
These are forecasts, not certainties. But the direction of travel is clear. More estates will owe more inheritance tax in the years ahead, and executors will need to be prepared for a more complex process.