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Explainer · last look 16 September 2026 Red diesel vs kerosene — two off-grid tanks, two prices They arrive on the same rural lorry. They are not the same liquid. Kerosene heats the house and tracks jet. Red diesel runs the tractor and tracks diesel. HMRC stamps them differently. April 2022 took red off most building sites. A 3.7p duty cut in June 2026 did not stop the farm price rising. Wholesale is the large slice. Duty is the small one. |
If you remember one sentence: kerosene is the house tank. Red diesel is the machine tank. Mix them and you break a boiler, a warranty, or the law.
How fast does each tank move?
|
Days Wholesale jet and gasoil. Both rural markets are thin. A Gulf week shows up on the ticket before it shows up on a city pump. |
1–14 days The delivered fill. No Ofgem cap. The next 500 or 1,000 litres is a live price, not a quarter-old photograph. |
Winter The house tank and the farm tank get booked in the same six weeks. That is why this page exists now. |
In laymen’s terms: two bottles in the same fridge. One is squash. One is engine oil. They both look like “oil”. Only one goes in the glass. The other goes in the lawnmower. The shop prices them off different warehouses.
What is in each tank?
| Kerosene (heating oil) | Red diesel (gas oil) | White diesel (DERV) | |
|---|---|---|---|
| British Standard | BS 2869 Class C2 | BS 2869 Class D | EN 590 road diesel |
| Also called | 28-second oil, kero, 28sec | 35-second oil, MGO, marked gas oil | Pump diesel |
| Colour | Clear to straw. Often dyed for heating. | Red — HMRC marker so a roadside test can see it | Undyed |
| Goes in | Domestic oil boiler | Tractor, combine, permitted machine | Lorry, van, car |
| Barrel slice | Kerosene / jet | Gasoil / diesel | Gasoil / diesel |
| Flash point (typical) | ≥38°C | ≥56°C | Higher than kero |
| Cold | Stays thin. Good in a frost. | Can wax. Winter grade matters. | Winter grade on the pump |
“28-second” and “35-second” are old Redwood viscosity nicknames. They are still how a lot of yards order. C2 is thinner. D is thicker. A domestic pressure-jet burner is built for C2. Put D in it and the nozzle, the flame and the warranty all notice.
The official stamp — HMRC, not the merchant
Duty is the bit the state prints. It is not the bit that moved the farm price this summer.
| Fuel, to 31 Dec 2026 | Fuel duty | VAT typical | HMRC source |
|---|---|---|---|
| White diesel / petrol (road) | 52.95p | 20% | Temporary 5p cut extended to 31 Dec 2026 |
| Marked gas oil (red diesel) | 6.48p | Usually 20% | Extra 3.7p cut from 15 June 2026 (was 10.18p) |
| Kerosene used as heating | Nil | 5% domestic | Full rebate. Heating kero has been nil duty for decades. |
| Kerosene in an excepted machine (not heating) | 6.48p | Depends | Same temporary cut as marked gas oil |
Source: HMRC “Amended Fuel Duty rates: 2026 to 2027”, 22 May 2026. Default path from 1 January 2027 is back up unless Budget 2026 says otherwise. VAT: GOV.UK VAT rates — heating oil for domestic use 5%.
| 52.95p road diesel duty |
6.48p red diesel duty now |
10.18p red diesel before 15 Jun |
0p heating kerosene duty |
That is why a farmer can look at a 193p pump and a 107p yard ticket and think the Treasury did them a favour. The favour is real. It is also small. Take 3.7p off duty and add 30p of wholesale and the tractor is still dearer.
What the tickets actually said in 2026
| 2026 window | Heating oil (kero) | Red diesel (farm) | White diesel (pump) |
|---|---|---|---|
| Jan–Feb, before the war | ~60–75p | ~72–78p | ~145–150p |
| March peak | 134p high (OilCompare, 8 Mar) | ~110–124p | ~180–192p |
| June (duty cut 15th) | ~83–95p | ~96p | 176.6p |
| 16 September 2026 | ~111–117p ex VAT | ~107p+ farm | ~193p pump incl VAT |
Heating oil: Fueltool UK average 117.26p/L ex VAT on 16 Sep 2026; OilCompare 111.0p same day. 1,000 L ≈ £1,231 incl 5% VAT (Fueltool). Red and white path: Passage Brief diesel explainer compiling AHDB / Farmers Weekly / DESNZ / RAC. Red is usually quoted ex-VAT to the farm. White is the pump including 20% VAT. Do not subtract them as if they were the same till.
| A worked 1,000-litre bill, mid-September 2026 | About |
|---|---|
| House tank — 1,000 L kerosene @ 117p ex VAT + 5% | £1,231 |
| Farm tank — 1,000 L red @ 107p (typical farm quote, ex VAT) | £1,070 before VAT |
| Same 1,000 L of white diesel at 193p pump | £1,930 |
The farm still pays less than the pump. That is the rebate doing its job. It does not mean the farm is cheap. It means the road is expensive.
Who is still allowed to buy red?
1 April 2022 is the line. Budget 2020 said most users would lose the rebate. Construction, quarries and general plant came off. Agriculture, rail and a short list stayed on. Excise Notice 75 is the live rulebook (updated 1 April 2026).
| Still permitted (if the machine and the job both fit) | Lost the rebate from April 2022 |
|---|---|
| Agriculture, horticulture, fish farming, forestry | Most construction plant on ordinary sites |
| Tractors and defined agricultural vehicles on defined jobs | General industry and commercial generators |
| Rail vehicles on rails | Most road-going plant that is not excepted |
| Golf courses and community amateur sports clubs | Private cars, vans, lorries — always white |
| Travelling fairs and circuses | Building a farm shed is not “agriculture” |
| Non-commercial heating and power; marine in GB with extra rules for pleasure craft | Putting red in a road tank — criminal, not a saving |
Two tests, not one. What the machine is, and what you are doing with it. A tractor cutting a hedge that borders a public road can stay on red. A JCB on a housing site cannot. HMRC tests the dye. The roadside does not take a story.
Why the two tanks do not move as twins
| 1 · Different slice — Kerosene is the jet cut. Red diesel is the gasoil cut. A week that squeezes jet lifts the house tank first. A week that squeezes diesel lifts the tractor first. |
| ↓ |
| 2 · Different tax — House kero: nil duty, 5% VAT. Farm red: 6.48p duty, usually 20% VAT. Road white: 52.95p duty, 20% VAT. Tax sets the gap. Wholesale sets the jump. |
| ↓ |
| 3 · Same thin market — Both fills are small tanker drops. Fewer buffers than a supermarket forecourt. That is why both jumped more, in percentage terms, than the pump in the 2022 CMA story — and why they still twitch harder now. |
Read the sister page if you want the jet lecture: why heating oil jumped when diesel did — and why it jumped more. This page is the farm-and-house split of that same barrel.
What you must not do
| Temptation | Why it fails |
|---|---|
| Red in the road tank | The dye is the point. DVSA / HMRC can see it. Duty unpaid on a road mile is not a loophole. |
| Red in the house boiler | Wrong class, wrong viscosity, wrong flash point. Soot, nozzle wear, voided warranty. It is not a cheaper C2. |
| Kero in the tractor | Wrong lubrication and flash. Excepted-machine kero exists as a legal category — it is not “pour the house tank into the John Deere”. |
| “Construction is off-road so red is fine” | Not since 1 April 2022. Off-road is not the test. Excepted use is the test. |
What should a household or a yard do?
| If you | Treat the next fill as |
|---|---|
| A house on kerosene | A jet ticket with 5% VAT and no cap. Budget the winter drop now. See heating oil vs diesel. |
| A farm still entitled to red | A diesel ticket minus most of the duty. The June cut is 3.7p. Wholesale is tens of pence. Order on the molecule, not the press release. |
| A builder | White. Price the job on 193p-class diesel, not on a 2021 red memory. |
| Running both tanks on one yard | Separate bowsers. Separate invoices. The dye is not a colour scheme. |
The short answer
Red diesel and kerosene share a lorry and a postcode. They do not share a slice of the barrel, a duty stamp or a legal use. The house tracks jet, pays no duty and 5% VAT. The tractor tracks diesel, pays 6.48p duty until the end of 2026, and usually 20% VAT. Construction lost the red entitlement in April 2022. A duty cut does not cap a wholesale spike. Do not swap the tanks.
House tank: heating oil versus diesel · Pump: fuel that moves the lorries · Bill: why a UK gas bill can still feel Hormuz · Board: are the sea routes into the UK open?
HMRC, Amended Fuel Duty rates 2026 to 2027, 22 May 2026: marked gas oil 6.48p/L from 15 June to 31 Dec 2026 (was 10.18p); heavy oil diesel 52.95p; heating kerosene full rebate / nil. GOV.UK VAT rates: heating oil for domestic use 5%. Excise Notice 75, updated 1 April 2026: excepted machines and permitted uses. Finance Act / April 2022 entitlement cut: agriculture, horticulture, forestry, fish farming, rail, specified leisure and non-commercial heating retained; most construction and industry removed. HMRC Oils Technical Manual HCOTEG12780: marked kerosene full rebate; marked gas oil partial rebate. Fueltool, 16 Sep 2026: UK heating oil 117.26p/L ex VAT; 1,000 L ≈ £1,231 incl VAT. OilCompare, 16 Sep 2026: 111.0p/L; 12-month high 134.2p on 8 Mar 2026. Passage Brief diesel explainer / AHDB / Farmers Weekly / DESNZ / RAC for the 2026 red and white path. BS 2869 Class C2 vs Class D for the two specifications. Not legal advice. Not a price forecast. Passage Brief records the passage between the headline and the British till.