How UK Fuel Prices Are Calculated and Updated in 2026
By FuelRoute · 2026-07-28
UK fuel prices move almost every day. One week petrol feels manageable, the next it’s jumped a few pence and you’re left wondering why. The government doesn’t set the price you see on the board. Retailers do. But the number they put up is the end result of a chain that starts with global oil markets and ends with a decision on a forecourt computer.
Here’s how that chain works in 2026.
What makes up the price of a litre
A typical litre of petrol or diesel is built from several clear parts.
First comes the wholesale cost. This covers the price of crude oil on the international market, the cost of refining it into petrol or diesel, shipping it to the UK, and the biofuel content that has to be blended in (E10 for petrol, B7 for diesel). Crude is priced in US dollars, so the strength or weakness of the pound against the dollar has a direct effect. When the pound drops, UK wholesale costs rise even if the oil price itself stays flat.
Next is the retailer’s margin. This is the amount the petrol station keeps to cover staff, maintenance, credit card fees and profit. Supermarket forecourts usually run thinner margins than independent or motorway sites. That is one reason the same fuel can cost noticeably more on a motorway than at the local Asda or Tesco.
Then come the taxes. Fuel duty is a fixed amount charged by the government on every litre. In 2026 it sits at 52.95 pence per litre for both petrol and diesel. That figure already includes the temporary 5p cut first introduced in 2022 and later extended. The cut is still in place until the end of 2026.
On top of everything — the wholesale cost, the margin and the duty — VAT is added at 20%. Because VAT is calculated on the total, you pay tax on the duty as well. Depending on the oil price, tax (duty plus VAT) often makes up between 50% and 60% of the final pump price.
How the price gets updated
Wholesale prices change daily, sometimes more than once, as oil markets and currency rates move. Retailers watch those wholesale figures closely. Most stations review their prices once a day, usually overnight or early in the morning, and set a new board price for the day. A few change more frequently if wholesale swings are large.
Supermarkets tend to lead the market. Because they sell a large share of the total volume, when they cut or raise prices other retailers often follow within a day or two. Independents and branded stations (Shell, BP, Esso etc.) can be slower or more cautious, especially if they bought fuel at a higher wholesale rate a few days earlier.
There is no legal requirement for stations to pass on wholesale falls immediately, and some hold prices longer than others. That is why you can still see differences of 5p or more between neighbouring forecourts even when the national average is falling.
The Fuel Finder system that started in 2026
Since early February 2026 every petrol station in the UK has been required to report its prices to a central open-data system called Fuel Finder. When a station changes its price it must upload the new figure within 30 minutes.
The data is then made available to comparison websites, apps and navigation systems. Drivers can now see near-real-time prices for stations near them instead of relying on yesterday’s averages or user-submitted reports. The aim is to make it easier to shop around and to put pressure on retailers to stay competitive.
If you notice a price on an app that does not match the board when you arrive, you can report the difference through the Fuel Finder service.
Where the official and reliable figures come from
The Department for Energy Security and Net Zero still publishes weekly average pump prices every Thursday. These are the official national averages for unleaded and diesel.
The RAC runs its Fuel Watch service, which tracks both wholesale and retail prices daily across supermarkets and other brands. The AA and commercial sites such as PetrolPrices also publish frequent updates and maps.
Between the government weekly figures, the RAC’s daily monitoring and the new Fuel Finder live data, it is easier than it used to be to see both the national trend and the cheapest stations near you.
What happens later in 2026
The current 52.95p duty rate is scheduled to remain until the end of December 2026. After that the temporary 5p cut begins to be withdrawn in stages, returning duty closer to the pre-2022 level of 57.95p. From April 2027 the government plans to start raising duty in line with inflation again.
Those future changes will add a few pence to the pump price on top of whatever the oil market is doing at the time. Until then, the biggest day-to-day drivers remain the crude oil price, the pound-dollar exchange rate, refining costs and how quickly individual retailers choose to pass wholesale movements on to drivers.
In short, the price on the board is a mixture of global markets, fixed tax, and the commercial decisions of the company that owns the pumps. Understanding the pieces makes the daily ups and downs a little less mysterious.
Fuel price data context is derived from the UK Government Fuel Finder Scheme, licensed under the Open Government Licence v3.0.