Inheritance tax reform has been keeping farmers awake at night - and with good reason. With APR and BPR under scrutiny, the future of family farm succession feels uncertain. CenTax’s new “minimum share rule” could reshape that debate.
Here’s what it means in practice, why it matters, and how to start preparing.
A changing landscape for farm succession
Few policy conversations have generated as much anxiety in Britain’s farming community as inheritance tax reform. Agricultural Property Relief (APR) and Business Property Relief (BPR) have long been the safety net that stops family farms being broken up just to pay an IHT bill.
That’s why alarm bells rang across the sector when the government proposed restricting these reliefs for deceased estates in October 2024. In response, the Centre for the Analysis of Taxation (CenTax) has put forward an alternative - the “minimum share rule” - aimed at protecting genuine farming businesses while clamping down on the use of farmland as a tax shelter.
The concept is simple enough, but the implications are significant.
How the minimum share rule works
Rather than asking only whether farm assets appear in an estate, CenTax’s model asks a deeper question: what proportion of the estate’s total value genuinely comes from farming or business activity?
To answer that, the proposal introduces a two-part test and three tiers of relief:
Test Part 1: Minimum share threshold
Agricultural and business assets must represent at least 60% of the estate’s total value to qualify for enhanced relief. Fall below that line, and the special treatment won’t apply.
- Tier 1 – Full relief
If the estate passes the 60% threshold, it receives 100% relief on qualifying assets up to £5 million per person. This is designed to protect the vast majority of family farms and ensure smooth intergenerational succession.
- Tier 2 – Partial relief
The next slice - £5 million to £10 million - attracts 50% relief, recognising the scale and ongoing economic value of larger but still actively farmed businesses.
- Tier 3 – No relief
Anything above £10 million gets no preferential treatment, and standard IHT applies. Larger and more diversified estates therefore shoulder a greater share of tax.
Test Part 2: If the 60% threshold is missed
The estate loses access to the tiered reliefs entirely. Only estates dominated by genuine farming or trading assets benefit from the enhanced framework.
Who this approach aims to protect
CenTax’s model is designed to raise the level of protection for real farming families while tightening the rules for passive investors holding agricultural land mainly to shelter wealth.
By focusing full relief on estates where farming represents a true majority of the balance sheet, CenTax argues the protected band can be increased from the government’s originally proposed £1 million to around £5 million per person - all without reducing tax revenues. Their modelling suggests this combination of a minimum share rule and a higher relief cap could be revenue-neutral or even positive because it blocks schemes that pair small qualifying holdings with much larger pools of unrelated wealth.
For most family farms, this is encouraging. Analysts broadly agree that a £5 million protected band would safeguard the overwhelming majority of small and mid-sized farms from having to sell land to meet IHT liabilities. And it shifts the burden onto estates with substantial non-farming assets - the main target of political concern.
But complexity and risks remain
Despite its intentions, the minimum share rule raises several practical challenges:
1. More complex probate and valuations
Calculating the farm-to-estate percentage means valuing every asset - including non-qualifying investments, holiday lets, pensions, and stakes in other businesses. That increases time, cost, and the likelihood of disputes. Classification questions (e.g., whether woodland is agricultural or investment property) will become flashpoints.
2. Cliff-edge risks for diversified farms
Mixed-use estates with renewables, lets, or non-farming property could find themselves just under the 60% line - losing all enhanced relief. For many modern businesses, diversification is essential, making this cliff edge particularly sensitive.
3. Continued need for succession and liquidity planning
The rule doesn’t remove the hard work of estate planning. Families with complex ownership patterns or substantial non-qualifying assets will still need strategies to ensure fairness, liquidity, and retirement income.
Possible behavioural and market consequences
If implemented, the new rule will shape market behaviour:
- Some third-party investment in farmland would be deterred - as intended - but investors may simply pivot to different asset structures.
- Larger estates might restructure to keep qualifying assets above the 60% threshold, creating new avoidance risks unless rules on trusts, subsidiaries, and connected parties are watertight.
- Transitional rules will be critical. Families who have planned succession under the current APR/BPR system could face significant disruption without phased implementation and clear guidance.
The bottom line
CenTax’s minimum share rule is an attempt to balance two competing goals: protect genuine farming families while preventing agricultural land from being used primarily as a tax shield.
If carefully drafted, the combination of a 60% threshold and a £5m full-relief band could significantly curb avoidance while safeguarding most family farms. But it comes with trade-offs: complex valuations, cliff-edge risks, and new behavioural incentives that policymakers will need to address.
In the meantime, farmers and advisers should start stress-testing their balance sheets - mapping qualifying and non-qualifying assets, checking the 60% threshold, and modelling scenarios around the £5m and £10m bands. Being prepared now means fewer surprises later.
Need help understanding how the minimum share rule could affect your estate?
Our dedicated Fortus Rural Economy specialists are here to walk you through the implications, run the numbers, and help you plan with confidence.
Reach out any time - we’re ready to support you.
