The EV reimbursement gap nobody wants to talk about
Here's a number that's sitting in the background of almost every UK fleet running electric vehicles right now, and almost nobody is talking about it openly.
HMRC's Advisory Electricity Rate, updated in March 2026, is 7p per mile for home charging and 15p per mile for public charging. Those are the rates HMRC publishes for employers to reimburse drivers of company EVs. They're updated quarterly, they're widely adopted, and they're the default most fleets have quietly settled on.
Now here are the numbers from Zapmap's February 2026 Price Index. Slow and fast public charging averaged 54p per kilowatt-hour. Rapid and ultra-rapid averaged 76p per kilowatt-hour. Translated to per-mile cost at typical real-world efficiency, that's roughly 16p per mile for slow and fast public charging, and roughly 23p per mile for rapid and ultra-rapid.
Compare those two sets of numbers and a structural gap appears.
HMRC's 15p public rate is close to Zapmap's 16p slow/fast number, so drivers using lamp-post and destination chargers are roughly breaking even. But drivers using rapid or ultra-rapid chargers — which is most drivers on most long journeys — are paying around 23p per mile and being reimbursed 15p. That's an eight-pence-per-mile shortfall being absorbed by the driver every time they plug in at a motorway service station.
Meanwhile, at the other end, drivers charging at home on a standard tariff come in somewhere between 7p and 10p per mile depending on the time of day. Drivers on a well-set-up off-peak EV tariff can come in as low as 3p per mile. So the HMRC home rate of 7p either matches reality or slightly over-reimburses — which means some home-charging drivers are being subsidised by their employer, while their rapid-charging colleagues are subsidising their employer.
This is not an accusation of bad faith on anyone's part. HMRC's rates are advisory averages. They can't track every tariff, every charge point operator, every regional variation. What they can do is give employers a defensible number to settle on. And most employers, understandably, have settled on it.
But "defensible" isn't the same as "accurate." And the longer the gap persists, the more it quietly eats into two things fleets actually care about: driver satisfaction (because the drivers who use public rapid chargers most are the ones who lose the most), and operating cost transparency (because the real cost of running the EV fleet is being distorted by whichever end of the charging curve your drivers happen to sit on).
There are three practical ways to close the gap.
The first is to reimburse on actual cost. This is the cleanest answer and the one most fleet managers instinctively want. The problem is that it requires you to know the actual cost of every charging session — which charger, which tariff, which driver, which vehicle. Until recently, that was nearly impossible to assemble without asking drivers to submit receipts for every stop, which nobody wants to do.
The second is to introduce a split rate — one for home, one for public — and update them more frequently than HMRC does. Several fleets are already doing this. It helps, but it still relies on averages, and it creates administrative overhead.
The third is to treat the reimbursement gap as a data problem and solve it with data. Which is what we're doing at Orbis IO.
Through our partnership with High Mobility, Orbis IO pulls OEM-native charging session data directly from the vehicle — start time, end time, kWh delivered, location, and (where available) charge point operator. We match that against the current public charging price index, the driver's home tariff where known, and the relevant HMRC rate at the time of the session. The output is a per-session reconciliation showing exactly what the driver paid, what HMRC says they should be reimbursed, and what the gap is either way.
For fleets running more than a handful of EVs, that reconciliation matters. Across a fleet of a hundred vehicles doing average mileage, the cumulative reimbursement gap over a year can run into tens of thousands of pounds — sometimes going one way, sometimes the other, depending on where the fleet's drivers tend to charge. Neither side of the gap is sustainable. Drivers who feel under-reimbursed eventually stop using rapid chargers when they should. Employers who over-reimburse home charging are carrying cost they don't see.
None of this is new information to fleet managers. The HMRC rates are public. The Zapmap index is published quarterly. The maths isn't complicated. What was missing, until now, was the data to reconcile individual charging sessions against the right benchmark at the right time — without asking drivers to take photos of their receipts.
That's the gap Orbis closes.
If you'd like to see how the reconciliation works on a real fleet, book a twenty-minute walkthrough. We'll run it on demo data, and if you're comfortable sharing a sample of your own charging history, we can run it on your numbers too.
Sources:
HMRC Advisory Fuel Rates including Advisory Electricity Rate, March 2026 — gov.uk
Zapmap Price Index, February 2026 — zap-map.com
Ofgem price cap, April 2026 — ofgem.gov.uk