Methodology note
Reverse farm inheritance-tax changes: calculation note
Scenario assumptions behind the Reverse farm inheritance-tax changes estimate. The figures are illustrative and exclude unrelated Conservative pledges.
Central fiscal result
+GBP 0.6bn - Net fiscal impact in 2028-29
Low case: +GBP 0.2bn. High case: +GBP 1.2bn. Positive numbers are fiscal costs or borrowing pressure. Negative numbers are Exchequer savings or receipts.
Scenario and baseline
- Model reversal of APR restrictions by 2028-29.
- Central cost assumes most current reform revenue is lost.
- Baseline is the post-2026 APR allowance regime.
- Business property relief is modelled separately.
Affected population
- Affected population is estates claiming agricultural property relief.
- Direct beneficiaries are heirs of qualifying farm assets.
- Indirect exposure includes land markets and tenant farmers.
- Most small claims are already below the allowance.
Gross impact
- Central cost: GBP 0.6bn annual lost IHT revenue.
- Low case assumes tight active-farmer eligibility.
- High case assumes wider planning and land-price effects.
- No food-supply GDP benefit is scored.
Fiscal build-up, central case
- Lost inheritance-tax receipts: +GBP 0.6bn
- Reduced forced-sale disruption: GBP 0.0bn
- Administration and compliance: GBP 0.0bn
- Avoidance response: GBP 0.0bn
Central net impact: +GBP 0.6bn in 2028-29.
Behaviour and pass-through
- Low case assumes only active farms benefit.
- Central case assumes most relief restriction is reversed.
- High case assumes expanded estate planning increases claims.
- Land-price effects benefit owners but not workers.
- No broad productivity effect is assumed.
Phasing
- 2026-27: +GBP 0.1bn. Preparation or partial implementation.
- 2027-28: +GBP 0.5bn. Main ramp-up year.
- 2028-29: +GBP 0.6bn. Target-year central estimate.
- 2029-30: +GBP 0.6bn. Continuation at steady-state assumptions.
Main source groups
- con-plan-2026: Conservative live policy page; used to identify current pledge wording.
- apr-bpr-2026: APR/BPR policy note; inheritance-tax relief distribution and revenue baseline.
- autumn-budget-2024: Autumn Budget baseline for tax measures Conservatives would reverse.
- hmrc-ready-2025: HMRC tax ready reckoners; main tax-cost anchor.
- mirrlees-2011: Tax design principles; informs behavioural and incidence assumptions.
- saez-slemrod-giertz-2012: Taxable-income responses; informs behavioural and incidence assumptions.