It has been more than a week since the later-than-usual Autumn Budget, and we think the new proposals could have an unintended consequence that will bring an age-old challenge for the auto industry back in the spotlight.
The 2025 Autumn Budget has introduced a new per-mile road tax for battery EVs and plug-in hybrid EVs. From April 2028 BEV owners will be charged £0.03 per mile driven, and PHEV owners charged £0.015 per mile.
The government has introduced this tax to plug the expected fall-off in fuel duty as the British vehicle parc electrifies. Right now, fuel duty brings in £24.4bn of government revenue every year – roughly 0.7% of GDP. By 2050, assuming that 90% of cars on the road are BEVs or PHEVs, the Office for Budget Responsibility projects that fuel duty revenue will fall by over 85% to just 0.1% of GDP.

For the government, this fall-off in revenue is worrying. Especially given the annual hollering that accompaniespothole season in the UK and the scale of the investment needed to fix our road network.
On the other hand, EV adoption is one of the government’s major policy planks. Because of this, the government is intending to make the per-mile EV tax cost BEV drivers less than half of the equivalent fuel duty levy, on a mile-by-mile basis.
Regardless, this has led to an awkward situation where the government is simultaneously subsidising and taxing the EV industry: in the same budget, the chancellor raised the total funding for the Electric Car Grant to £2bn, and raised the threshold for the Expensive Car Supplement by £10,000.
Since the government needs to find a way to compromise between two goals that are at tension with one-another – revenue stabilisation versus EV adoption – the result is what perceptive analysts like to call “a fudge”.
Was it a successful fudge? On paper, it could be. The OBR estimates that the net effect of all budget measures will 120,000 fewer BEVs and PHEVs sold between now and March 2031. This seems large but is the equivalent to 20% of their 2024 sales. Spread out over five years, that means an annualised drag of less than 5% on sales. And if EV demand starts growing again as the petrol and diesel sales ban approaches, that means the industry will only incur an opportunity cost from the EV road tax, rather than an actual cost.
The devil, as always, lies in the details. And this is where a familiar issue raises its head. So far, the idea is to take annual mileage at an MOT centre and feed it into the DVLA’s database. This wipes out one advantage of getting a new car, which typically only need to visit an MOT centre after three years on the road. But the killer problem is reliably taking odometer readings.
Odometer fraud has been used to inflate used car values for decades, and is already prolific: 1 in 7 used carshave had their odometer tampered with, or ‘clocked’, according to recent research. This is because it’s easier than ever to alter mileages. With vehicle software having replaced many of the burdens carried by hardware, adjusting the odometer requires little in the way of expensive tools or mechanical know-how.
As a result, the internet is awash with consumer-friendly “rollback” packages that can change a vehicle’s odometer readings within a few minutes. And they’re getting easier to run in newer vehicles, leveraging the same functionality that delivers over-the-air software updates.
Now, however, it’s not just used car retailers that have an incentive to commit odometer fraud. Every EV driver will now stand to benefit by adjusting their mileage, with the process potentially taking minutes. Howautomotive brands and the government address this – if they can – is going to be key to the credibility of the new tax.
Image by Kathy McNeely from Pixabay



