Farmer Tax UK 2026/27: Farm Profit Averaging, AIA and the Real Bill on a Working Farm

Why farming needs its own tax rules

Farming profit is uniquely volatile — a bumper harvest one year followed by drought, flooding or a commodity price crash the next is the normal pattern, not the exception. Because UK income tax is progressive (20% basic rate, 40% higher rate, 45% additional rate), a farmer whose profits swing between £15,000 in a bad year and £65,000 in a good year pays significantly more tax over the two years, unaveraged, than a farmer with a steady £40,000 profit each year — even though the total two-year profit is identical. Farm profit averaging exists specifically to correct this unfairness.

Worked example: farm profit averaging in practice

Without averaging — Year 1: £62,000 profit, Year 2: £18,000 profit

Year 1 tax: (£37,700 × 20%) + (£11,730 × 40%) = £7,540 + £4,692 = £12,232 (income tax only, ignoring NI for simplicity) Year 2 tax: (£5,430 × 20%) = £1,086 Total unaveraged tax: £13,318

With averaging — both years treated as £40,000 profit

Year 1 tax: (£27,430 × 20%) = £5,486 Year 2 tax: (£27,430 × 20%) = £5,486 Total averaged tax: £10,972

Saving from averaging: £2,346 across the two years, purely from smoothing the same total two-year profit (£80,000) evenly rather than letting the good year push income into the 40% band unnecessarily.

This example uses simplified figures to illustrate the mechanism — real farm accounts involve more moving parts (capital allowances, other income, NI), but the underlying principle — averaging reduces total tax when profits are volatile and cross rate-band boundaries — holds generally.

Two-year vs five-year averaging

Two-year averaging compares the current year's profit against the previous year. If one year's profit is less than 75% of the other (i.e. they differ by more than 25%), you can elect to average the two — each year's profit becomes the mean of the two.

Five-year averaging, a more recent addition specifically for farmers, allows averaging across five consecutive years, which can be more effective at smoothing longer cycles — a run of poor harvests followed by a strong year, for example, might not trigger the simpler 2-year test cleanly but benefits from the wider 5-year window. Farmers can choose whichever averaging approach produces the best result, subject to the specific election rules and time limits (claims must generally be made within a set period after the second year's return).

Capital allowances on farm machinery and buildings

Farm machinery — tractors, combines, balers, sprayers, livestock handling equipment — generally qualifies for the Annual Investment Allowance (AIA), giving a 100% deduction against profits in the year of purchase, up to the £1 million annual limit. For a farm buying a £150,000 combine harvester, this could mean the entire cost is deducted against that year's profit, potentially eliminating the tax bill in the purchase year (and interacting with averaging decisions — a very low-profit year from a big equipment purchase might not benefit as much from averaging as expected, so the two reliefs need to be planned together).

Agricultural buildings (grain stores, livestock sheds, new farm buildings) typically don't qualify for AIA but some structures may qualify for the Structures and Buildings Allowance, a flat-rate annual deduction spread over a longer period (currently 3% a year over roughly 33 years) — a much slower write-off than machinery.

The 2026 Agricultural Property Relief changes

The most significant recent change for farming families is the restriction to Agricultural Property Relief (APR) and Business Property Relief (BPR) for Inheritance Tax, effective from 6 April 2026. Previously, qualifying agricultural and business property received 100% IHT relief with no cap. From April 2026:

• The first £1 million of combined agricultural and business property per estate still gets 100% relief (no IHT)
• Value above £1 million gets only 50% relief, meaning an effective 20% IHT rate (half of the standard 40% rate) on the excess

For a working farm worth several million pounds — common given land values — this is a major change requiring careful succession planning: lifetime gifting strategies, life insurance to cover the potential IHT liability, and reviewing how farm ownership is structured between generations, all became significantly more relevant overnight.

Diversification income: a separate trade

Many farms now run a farm shop, holiday cottages or glamping pods, a wedding/events venue, or solar/renewable energy generation alongside core agriculture. HMRC generally treats these as separate trades for tax purposes — meaning the diversified income doesn't get folded into farm profit averaging, and the land used for non-agricultural purposes may not qualify for Agricultural Property Relief (though Business Property Relief might apply instead, subject to its own conditions and the new £1 million combined cap). Keeping clean, separate accounting records for the farming trade versus diversified activities from the outset makes both income tax reporting and any future APR/BPR claims considerably simpler.

self-employed-tax-uk