How the Government Could Track Your Hybrid Car to Charge You by the Mile From 2028

From April 2028, drivers of plug-in hybrid vehicles face a new road pricing charge under the government’s electric vehicle road duty scheme. But the system designed to make PHEV taxation fairer is already under fire from motoring groups, industry bodies and privacy campaigners — and the central argument comes down to a single contested assumption buried deep in Treasury modelling.

The eVED system will charge pure electric vehicles 3p per mile and plug-in hybrids 1.5p per mile. The reduced rate for PHEVs reflects the fact that these cars split their journeys between petrol and electric power. But the 1.5p figure is not based on individual driving behaviour. It is based on a government assumption that PHEV drivers spend exactly 50% of their mileage running on electric. For a growing number of owners, that assumption is wrong — and it could cost them.

What the eVED System Will Actually Charge Hybrid Drivers

The eVED, or electric vehicle road duty, replaces vehicle excise duty for zero and low-emission vehicles from April 2028. For pure EVs, the rate is set at 3p per mile, designed to recover some of the road maintenance revenue lost as fuel duty receipts fall. The Office for Budget Responsibility has warned of a £12 billion fuel duty black hole by 2030 as combustion engines disappear from new car sales.

PHEVs sit in a middle category. Because they can run on either electricity or petrol, the Treasury has set their rate at half the EV level: 1.5p per mile. The logic is that if a PHEV covers 10,000 miles in a year, it will spend roughly 5,000 of those miles on electric power and 5,000 on petrol — and it should only be charged the electric rate for the electric portion.

The problem is that this 50/50 split is a flat average applied to every PHEV regardless of how the car is actually driven. An owner who charges their vehicle daily and drives mostly shorter local journeys might achieve 70% or 80% electric running. A company car driver who rarely charges and spends most of their time on motorways might run almost entirely on petrol. Under the current flat-rate model, both pay exactly the same per mile.

The Problem With the Government’s 50% Assumption

Silviya Barrett, director of the Campaign for Better Transport, has raised particular concern about drivers who use their PHEVs predominantly in petrol mode. “If a driver is only achieving 20% electric running, they will be paying the same per-mile charge as someone achieving 80% electric running,” she said. “That is not a fair reflection of their actual contribution to road use or emissions.”

The reverse problem also applies. A driver who charges consistently and runs mostly on electricity is paying a per-mile rate calibrated for someone using petrol half the time. This group effectively subsidises those who do not charge. The flat rate creates an incentive structure that rewards those who treat their PHEV as a conventional petrol car while penalising those who actually use the electric capability.

Research from Zap-Map published earlier this year found that PHEV electric running rates vary enormously depending on ownership type. Private owners who install a home charger typically achieve between 55% and 70% electric running. Company car drivers without charging at home average closer to 25%. The 50% assumption lands in the middle but captures neither group accurately.

How Telematics Could Track Your Driving

The industry’s proposed solution is telematics — using the vehicle’s existing onboard technology to distinguish between electric and petrol miles and charge accordingly. The technical groundwork is already there. Since 2018, every new car sold in the European Union and United Kingdom has been required to include an eCall system, a mandatory emergency call function triggered automatically in a crash. The eCall system requires a built-in SIM card and GPS receiver.

What the industry is now proposing is that this existing hardware, already present in every PHEV sold since 2018, could be used to log whether the vehicle’s drivetrain is operating in electric or petrol mode during each journey. The data would not need to record where the car goes — only which mode it is using and for how many miles. This, proponents argue, would allow per-mile billing that accurately reflects actual electric running without building new infrastructure or requiring drivers to install additional devices.

The Society of Motor Manufacturers and Traders has backed the telematics approach in principle, arguing it is the most technically straightforward route to accurate billing. But manufacturers have also cautioned that any scheme would require clear legislation governing what data is collected, who holds it, how long it is retained, and who can access it.

The Privacy Question That Is Making Drivers Nervous

Driver resistance to telematics is not primarily about the technology itself. It is about trust. A YouGov survey commissioned by the Electric Vehicle Association found that only 25% of EV and PHEV drivers said they would support mileage-based road pricing if it required a device that could track their location. Support rose to around 55% when the question was framed around a system that recorded only mileage and driving mode with no location data attached.

The distinction matters because the eCall GPS receiver technically has the capability to record location as well as distance. The question of whether a future road pricing system would confine itself to mileage data — or expand to include journey routes — is one that the government has not yet answered definitively. Civil liberties groups have called for any enabling legislation to include explicit prohibitions on location logging, with criminal penalties for any public or private body that stores route data.

There is also the question of who administers the scheme. Previous government consultations on road pricing have considered both a DVLA-run public model and a private sector billing model similar to those used in mobile phone contracts. Each carries different data retention risks, and the debate has not been resolved as the 2028 start date approaches.

What the Industry Wants the Government to Do

Vicky Edmonds, chief executive of the Electric Vehicle Association, has called for the PHEV eVED rate to be delayed until at least 2030. Her argument is that the government does not yet have a workable telematics framework in place, that the flat-rate assumption is demonstrably unfair to high-charging PHEV users, and that introducing a flawed system in 2028 will undermine confidence in electric vehicle ownership at a critical moment for the transition.

“We are not opposing road pricing in principle,” Edmonds said. “We are opposing a system that charges PHEV drivers by assumption rather than by fact. If the government wants drivers to trust the eVED, it needs to get the methodology right before it goes live.”

The Campaign for Better Transport has taken a different position, arguing that the flat rate should stay for now but should be reviewed after the first full year of operation with real-world data. Barrett has also called for lower rates for drivers who can demonstrate high electric running through voluntary telematics — a carrot rather than a stick approach that would allow early adopters to benefit without mandating tracking for all.

What PHEV Owners Should Do Now

With 2028 still two years away, there is no action required from current PHEV owners immediately. But there are practical steps worth taking now. First, check whether your vehicle was manufactured after September 2018 — if it was, it almost certainly contains the eCall SIM and GPS hardware that would underpin any telematics scheme. Vehicles made before that date may need additional hardware if a tracking-based system becomes mandatory.

Second, keep a record of your actual electric running if you want to make a case for a fairer rate. Many modern PHEVs display lifetime electric running percentages in their infotainment systems or through companion apps. This data could become relevant if the government introduces a voluntary accurate-billing scheme as an alternative to the flat rate.

Third, respond to the government’s ongoing consultation on eVED implementation. The Department for Transport is expected to publish a further consultation paper in the second half of 2026 covering the PHEV rate specifically. Industry bodies and motoring groups have urged individual drivers to submit responses, arguing that the volume of public feedback will influence whether the 2028 start date holds or whether a delay and redesign is forced.

The eVED is coming. But whether it charges you fairly will depend on decisions made in the next 18 months — decisions that are still very much in play.