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Red diesel (gas oil)

Certas Energy is a reliable supplier of competitively-priced red diesel (gas oil), with over 900 tankers available to deliver fuel to businesses nationwide.

Red diesel delivered to you

Red diesel – also known as gas oil – is a diesel fuel used for heating and back-up power generation, as well as some off-road applications. Its use has become restricted to mostly non-commercial purposes since duty equalisation legislation was introduced in April 2022.

As the UK’s largest independent distributor of fuel and lubricants, Certas Energy is a reliable, competitively priced, local supplier of red diesel.

Whether you’re looking to buy red diesel or to find a suitable alternative following the red diesel duty reform – we’re here to help. 


Red diesel, also known as gas oil or tractor diesel, is a low tax fuel used in off-road vehicles and machinery only. Due to duty equalisation, red diesel is no longer subsidised for the majority of sectors and uses, including construction and most commercial applications.

Red diesel is essentially the same as white diesel, but it contains a red dye to identify illegal usage. It is cheaper due to lower fuel tax duty.

The price of red diesel changes daily due to influences from the global oil market.

Certas Energy is proud to be a competitive red diesel supplier and can deliver red diesel to customers across the UK. For today’s red diesel prices, request a quote online.


Red diesel duty reform was introduced as part of the government’s move to drive forward the net zero carbon 2050 agenda.

Red diesel usage is now restricted to the following qualifying purposes:

  • For vehicles and machinery used in agriculture, arboriculture, horticulture, fish farming and forestry
  • To propel passenger, freight or maintenance vehicles designed to run on rail tracks
  • For heating and electricity generation in non-commercial premises, including state schools and hospitals
  • For maintaining community amateur sports clubs as well as golf courses
  • As fuel for all marine craft refuelling and operating in the UK, except for propelling private pleasure craft in Northern Ireland
  • For powering the machinery of travelling fairs and circuses

It cannot be used for:

  • Most commercial purposes
  • Machinery or equipment used in construction
  • Heating applications in commercial environments

If you would like to kick-start your energy transition today, explore your options in our alternative fuels guide.

Red diesel can only be purchased from specialist fuel suppliers. The fuel is heavily regulated and misuse can lead to legal repercussions, so it’s important to buy from a reliable supplier.

Certas Energy is an industry leading red diesel fuel supplier. As the UK’s largest fuel distributor, we can provide a reliable supply of quality red diesel. Call 0345 600 4040 to speak to your local team or request a quote online.


Certas Energy HVO is a 100% biodegradable drop-in replacement for red diesel that can help businesses to lower CO2 greenhouse gas emissions by up to 90%. The renewable diesel offers several benefits, including long shelf life, low temperature performance, and improved combustion.

GTL Fuel is another cleaner, quieter, longer-lasting diesel alternative that significantly reduces NOx and Particular Matter emissions, is biodegradable and non-toxic and minimises machinery downtime due to fewer filter changes.

If you are affected by the red diesel changes, or would like to finder a cleaner alternative to red diesel, check out our Fuelling Futures page.


Your guide to gas oil

Find out everything you need to know about red diesel – or gas oil – from what it is and how it’s made, to who can use it and the latest regulatory updates.


Fuel your mind with all the facts

We’ve got you covered for the red diesel duty equalisation changes with our sector-specific infographics – detailing what red diesel can and can’t be used for and the action you need to take.


Who do the changes affect?

From the sectors and applications no longer eligible for the use of red diesel, to the steps your business should be taking, watch our video to discover what you need to know about the tax changes.

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Find your local Certas Energy team with our handy locator map


Still got questions? Read our red diesel FAQs

Red diesel duty equalisation is one of the biggest shifts in fuel regulation in decades. You can get answers to the most frequently asked questions about the red diesel changes in our blog which will bring you up to speed with what you need to know.


Looking for more information?

Take a look at our informative guides on the red diesel changes for the Agricultural, Haulage and Construction industries.

Why choose Certas Energy as your red diesel supplier?

Assured Nationwide 2

Nationwide delivery

130 local depots across the UK and 900 tankers delivering red diesel nationwide

Fuel Products

Assured and reliable supply

Quality red diesel from reputable refineries delivered when and where you need it, from 500 to 36,000 litres.

Competitive Pricing

Competitive pricing

Flexible payment options and credit terms, as well as competitive red diesel prices.

Excellent Customer Service

Expert support and service

Everything you need to keep your business moving and navigate the post-red diesel reform landscape.

Contact our fuel team for red diesel advice and prices

If you have any questions or want to get a red diesel price based on your requirements, contact our fuel team today.

Contact us today to order red diesel

Call 0345 600 4040 to speak to your local team or request a quote via the form below:

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Alternatives to red diesel

If your business is no longer eligible to use red diesel, you may be unsure where to start with alternative fuels.

From Gas to Liquid (GTL) Fuel to Hydrotreated Vegetable Oil (HVO) there are a number of drop-in, lower emission alternatives to red diesel that are readily available today.

If you’re considering cleaner-burning red diesel alternatives, we have the products and expertise to help your business make the smart, sustainable choice.

We're a verified supplier of renewable fuels

Certas Energy is part of the Renewable Fuels Assurance Scheme. 


Diesel Defender

Diesel Defender is a liquid anti-theft marker dye for UK non-rebated fuel, also known as white diesel, road diesel or DERV. The dye colours white diesel to produce a green fuel and acts as a powerful deterrent to thieves.

It has become more popular since red diesel reform, as many users made the switch to colourless regular diesel, which is more vulnerable to theft as it lacks the tell-tale red dye.

Diesel Defender can be used in a wide range of applications, including construction equipment, cooling or heating units in road and rail transport, airport vehicles, forklift trucks, electricity generation and heating for commercial premises.

Read more about Diesel Defender and preventing fuel theft using the links below.

Red Diesel FAQ

Here, we have put together a series of Frequently Asked Questions based on what customers are asking us about red diesel. 
Got another question? Get in touch

Like many forms of fuel, red diesel is derived from crude oil that has been extracted from the ground. The crude oil is heated and distilled to become gas oil, and red dye is added to the final product to give it its distinct colour and make it easily recognisable against colourless road diesel. The red dye alerts HMRC inspectors to any misuse of the rebated fuel. 

Red diesel fuel is the same as white diesel fuel; the only difference is that it contains a red dye to identify illegal usage. Red diesel is cheaper than white diesel due to lower fuel tax duty as it is heavily rebated. Due to duty equalisation, red diesel is no longer subsidised for all uses, including construction and most commercial applications. For more information on who can use red diesel and what for, read our blog on the red diesel duty changes

No, red and white diesel must not be mixed. For those who use both red and white diesel – such as farmers – supplies must be kept separate, and machinery tanks and supply lines must be flushed in-between permitted and non-permitted uses in order to remain compliant.  

Certain vehicles, such as diggers, may use red diesel in permitted settings for permitted uses. 

For example, a digger can use red diesel if it is for an application on agricultural land and is an accepted agricultural activity. However, a digger on a construction site would not be permitted to be powered by red diesel, as this is a non-permitted, commercial activity.  

At Budget 2020, the government announced that it was removing entitlement to use red diesel from most sectors from 1 April 2022. Duty equalisation was introduced as part of the government’s move to drive forward the net zero carbon 2050 agenda. 

Removing most red diesel entitlements was intended to incentivise users of polluting fuels like diesel to improve the energy efficiency of their vehicles and machinery, invest in cleaner alternatives, or use less fuel. If you would like to kick-start your energy transition today, explore your options in our alternative fuels guide

The price of red diesel changes daily due to influences from the global oil market. Prices can also depend on quantity and location, so the price of red diesel really depends on the order being placed and what’s currently happening in the market.  

Certas Energy is proud to be a competitive red diesel supplier and strive to offer customers a great red diesel price. Find out today’s red diesel prices by speaking to a member of our friendly team on 0345 600 4040 or request a quote online and your local team will come back to you. 

Yes, farmers can still use red diesel. For the most part, the agricultural industry is unaffected by red diesel duty equalisation and farmers can carry on using tractor diesel in much the same ways as before. However, accepted use of red diesel in agriculture has become more restricted and there are exceptions. Check out our blog on what farmers need to know about red diesel duty equalisation

Red diesel can be used for non-commercial heating but can no longer be used by industries as a heating oil or for power generation in a commercial setting. 

However, cost-effective alternative heating solutions are available, including industrial heating oil/Therma35 and kerosene

Yes there are alternatives to red diesel that are readily-available. As well as standard white diesel/DERV, there are cleaner diesel alternatives that are becoming increasingly available, including OEM approved fuel, GTL Fuel (Gas-to-Liquid), and renewable diesel Hydrotreated Vegetable Oil (HVO), (dependent on usage, duty may still apply). Both fuels can help lower emissions and accelerate businesses’ net zero ambitions. 

Yes, red diesel storage is subject to regulations. However, these vary across different regions and are dependent on type and use of tank. It is recommended to check with local councils for specific guidance. 

In England, if more than 200 litres are stored, Control of Pollution (Oil Storage) (England) Regulations 2001 must be adhered to. To comply, the fuel dispensing hose must be within a locked cabinet and any drips contained within the bund. Further information on oil tank regulations can be found in our guide

It is important to note that there are different rules for agriculture where fuel is used specifically for agricultural purposes, such as powering a tractor or grain dryer. Check out our blog for more information on storing fuel safely on farms.  

Failure to adhere to the oil tank regulations can result in considerable fines or even prosecution. 

Certas Energy tank specialists are available to provide product and installation guidance. We also offer a full range of fully compliant fuel storage tanks. To learn more about our range or to speak to one of our specialists today, click here.  

No, you don’t need a licence to purchase red diesel but you must be an eligible user and sign an RDCO form upon purchase. You must only buy red diesel from a company who is HMRC registered.  

To determine if you are a permitted user, see our red diesel duty FAQs blog

Yes, red diesel does expire but can last around 12 months if stored correctly. 

To maximise shelf life, keep it in a dry, cool environment and use fuel additives to prevent bacterial growth, water contamination, and build-up. For guidance on the right additives to use, speak to one our specialists.  

The rate you pay can depend on the quantities purchased and uses. To apply to reclaim fuel tax, you can fill in the HO27 form

HMRC and police authorities can spot check for red diesel by dip testing fuel tanks. If there is red dye present, it stains the dipstick, identifying the fuel as red diesel. Using red diesel outside of the regulations is subject to significant fines, seizure of vehicles and even prosecution. 

Want to ensure you are complying with the red diesel rules? Download our handy compliance checklist

Fuelling futures together

From red diesel tax changes to cleaner alternatives, if you need more information, chat to our experts today.

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