Petrol Is Up 8p in a Month and Duty Rises on 1 September: The UK Fuel Market in July 2026

June was a remarkable month at the pumps. Prices fell at a pace rarely seen in UK fuel retailing, and drivers who filled up in early July paid less than at any point since the spring.

That window has closed. Between 15 and 29 July, the price of petrol rose at almost every forecourt in the country. Not most of them – almost all of them.

What Prices Are Doing Right Now

The figures below come from Fuel Finder's own database on 29 July 2026, covering every forecourt in the government price feed that has reported within the last 14 days – 7,737 stations out of 8,046 active sites.

A 55-litre fill of petrol therefore costs around £87.60, and the same tank of diesel about £97.85.

One note on method, because it changes how these numbers compare to others you will see quoted. This is an unweighted average: every forecourt counts once, from a Highland single-pump site to a Tesco Extra. Figures published by motoring organisations are typically weighted by sales volume, which pulls the average down because supermarkets sell a disproportionate share of the UK's fuel from a small number of very busy sites. Both are valid; they answer different questions. The unweighted figure tells you what a typical forecourt is charging, which is the more useful number when you are deciding where to stop.

The Reversal, in Numbers

Comparing today's national average against a historic one can mislead, because the set of reporting stations changes from day to day. The table below avoids that: it takes the stations reporting fresh prices today and compares each one against its own price at earlier dates. Same forecourts, like for like.

Two things stand out.

First, the recent move is broad and one-directional. Of 7,014 forecourts with a comparable price from a fortnight ago, 6,913 had raised petrol, 78 had left it unchanged and just 23 had cut it. Price rises that uniform are a wholesale story, not a retailer story – when costs move this sharply, every operator follows within days.

Second, and this is the part worth holding on to: the 60 and 90-day columns are still flat or negative. Petrol is essentially where it was two months ago, and diesel is still 10.6p cheaper than it was in late April. July has clawed back a large fall rather than broken new ground. That is a materially different situation from a sustained climb, and it should temper any instinct to panic.

Why It Happened: Crude Oil

Brent crude, converted from the daily closes Fuel Finder records from the US Energy Information Administration, tells the story plainly:

• 18 May 2026: $116.73 a barrel
• 2 July 2026: $68.53 – the lowest close since the series began in May
• 20 July 2026: $86.99

That is a 27% rise in 18 days, following a fall of more than 40% from the mid-May peak. Sterling did not cushion it: measured in pounds, Brent went from £51.43 to £64.63 a barrel over the same period.

The spring spike and its unwinding were driven by geopolitical risk in the Gulf and the market's subsequent repricing of that risk. Reporting on the specific causes of the July rebound varies considerably in quality, so this article does not attribute it to a single event. What is not in doubt is the direction and scale of the move, and that UK pump prices followed it almost exactly on the expected lag.

One caveat on timing: the EIA publishes with a delay of several days, so 20 July is the most recent confirmed close available at the time of writing rather than today's price.

Fuel Duty Rises on 1 September

The second thing shaping the months ahead is tax, and it is already legislated.

Fuel duty has been 52.95p per litre since the temporary 5p cut was introduced in March 2022. The Autumn Budget 2025 confirmed that cut will be withdrawn in stages:

The pump effect is larger than the duty change because VAT is charged on top of duty. A 1p duty rise becomes roughly 1.2p once 20% VAT is applied.

In cash terms, the September increase adds about 66p to a 55-litre fill. By March 2027, with the full 5p restored, the same tank costs around £3.30 more than today on duty alone.

It is worth seeing how much of the current price is already tax. At 159.3p for petrol, duty is 52.95p and VAT is 26.6p – just under half the pump price, before the retailer, refiner or oil producer takes anything.

There is a fuller breakdown of the phased increases in the guide to the September 2026 duty rise.

Where You Fill Up Beats When

Timing gets the attention, but the spread across forecourts is far larger than any week-to-week movement. On 29 July the cheapest petrol in the UK was 139.9p and the dearest 198.0p – a range of 58p per litre, or nearly £32 on a single tank.

By brand

Grouped, the four big supermarkets plus Costco average 156.5p for petrol against 160.0p everywhere else – a gap of 3.5p. For diesel the gap is wider at 5.1p (173.8p against 179.0p).

The gap between a supermarket and a Shell or BP forecourt is around 6p per litre, which is £3.30 on a 55-litre fill.

By region

Averaging petrol by postcode area across forecourts reporting fresh prices, Northern Ireland is comfortably the cheapest part of the UK at 153.0p across 456 sites. At the other end, the Highlands (IV) average 163.1p, with Chelmsford (CM), Hull (HU) and Portsmouth (PO) all near 162.5p. Northern England – Bradford, Wakefield, Oldham, Blackburn, Bolton and Manchester – clusters around 156.5–157.2p.

Motorways

The dearest mainland forecourts in the data are motorway services. Sites on the M74, M25 and M5 were charging 185.9p to 187.9p for petrol – roughly 27p above the national average, or about £15 extra per tank. Filling before you join, or at a town a mile off the junction, remains the single largest saving available to most drivers.

What Actually Helps

Advice is only worth giving if the numbers support it. These do.

In a rising market, do not run the tank down

With 98.6% of forecourts raising prices over a fortnight and petrol up 4.1p in the last week alone, deferring a fill has been costing money rather than saving it. On a 55-litre tank, last week's delay cost about £2.25.

This is advice for the current conditions, not a rule. In June the opposite was true, and drivers who delayed were rewarded. The signal to watch is the wholesale trend, not the price on the sign.

Do not drive far for a cheap forecourt

A car returning 45mpg burns roughly a litre every 10 miles. A 10-mile round trip to save 3.5p per litre on a 55-litre fill nets you about £1.93 in savings against £1.61 of fuel burned getting there – and that ignores your time entirely.

The saving is real when the cheaper station is on a route you were already driving. It rarely survives a detour.

Check before you commit, not after

Because the national spread is 58p and neighbouring forecourts routinely differ by 10p or more, a 30-second check before setting off is worth more than any driving technique. The UK fuel price index tracks the national picture, and the map shows live prices near you.

Diesel drivers: the gap is unusually wide

Diesel currently sits 18.7p above petrol. It also fell harder in June and has rebounded harder in July – up 12.4p in a fortnight against petrol's 7.7p. Diesel is the more volatile of the two fuels at present, which makes the case for filling on the way down and not waiting on the way up rather stronger.

On the September duty rise: plan, do not panic

An extra 1.2p per litre is about 66p on a tank. That is real money over a year – roughly £8 to £12 for a typical driver – but it is not a reason to queue on 31 August. Ordinary week-to-week wholesale movements have been five to ten times larger than this increase all month.

The December and March rises, and the return of annual inflation indexation from April 2027, matter considerably more over time than the first 1p does.

A Note on Forecourt Staff

Everything above points the same way: the number on the sign is set by crude oil markets, wholesale supply contracts and tax. Duty is legislated at Westminster. At supermarket and major-brand sites the pole price is set centrally, often hundreds of miles from the forecourt itself.

The person behind the till has no say in any of it. They cannot change the price, they were not asked about it, and most mornings they find out at the same time you do.

Both the Association of Convenience Stores and the shopworkers' union Usdaw report that verbal abuse of retail and forecourt staff remains well above pre-pandemic levels, and sharp price rises are a predictable flashpoint. A fortnight in which 98.6% of forecourts put their prices up is exactly the kind of stretch where that lands on someone who had nothing to do with it.

If a price makes you angry, the outlets that can actually change something are your MP on duty, and your custom going to a cheaper forecourt. The cashier is neither.

The Short Version

Fuel is more expensive than it was three weeks ago, and it got there quickly and almost universally. But it is not expensive by the standards of this spring – diesel is still more than 10p below its late-April level, and petrol is flat against two months ago.

The crude market drove the move, tax will add a little more from September, and neither is something a driver can influence. The 58p spread between the cheapest and dearest forecourt is. That is where the money is.

All price figures in this article are from Fuel Finder's database on 29 July 2026, covering forecourts in the government price feed that reported within the previous 14 days. Crude oil figures are US Energy Information Administration daily Brent closes. Duty rates and the phased increases are as confirmed at Autumn Budget 2025 and published by the Office for Budget Responsibility.