The rule is simple and catches a lot of sites out: if you sell electricity by the kilowatt hour, the meter you measure it with has to be legally certified for trade. In the UK and across Europe that means the Measuring Instruments Directive — MID. A charger without MID-certified metering can tell you how much energy it delivered, but that reading is not a legally acceptable basis for charging someone for it.
The expensive part is that metering is built into the charger at manufacture. You cannot bolt it on later. Sites that install without it and then decide to start billing per kWh face replacing the hardware.
When you need MID metering
You need it whenever money changes hands based on a kWh reading. That covers public pay-per-use charging, recharging tenants or leaseholders in a block of flats, billing between separate legal entities, and reimbursing or recharging staff where the amount is calculated from consumption.
You do not need it if charging is free at the point of use, if you charge a flat fee per session or per hour regardless of energy taken, or if you are only measuring consumption for internal reporting and cost allocation within one organisation. That last distinction matters — plenty of workplaces think they need MID when standard metering would do.
The flat-fee alternative
Charging a fixed amount per session sidesteps the requirement entirely, and on short-dwell sites it is often simpler for everyone. The trade-off is fairness: a driver taking 5kWh pays the same as one taking 40kWh, which works where sessions are broadly similar and annoys people where they are not. For a retail car park with a two-hour limit it is perfectly reasonable. For overnight charging at a block of flats it is not.
Which chargers have MID metering
It is a specification line, not a brand feature — several manufacturers sell the same charger with and without it, at a price difference of a few hundred pounds. Currently we stock:
- Sevadis MaxiCharger Gen 2 Digital — £660 for 7.4kW, £840 for 22kW, MID meter accurate to ±1%
- NexBlue Delta Max — £715, 22kW with MID metering built in
- Ratio io7 and io8 MID — from £2,600, dual socket, £300 more than the CT-metered version of the same unit
- Teltonika EVC2 — £690, internal meter accurate to better than 1%
MID versus CT metering
The Ratio range is the clearest illustration because both versions exist side by side. CT metering uses a current transformer and is accurate enough for load balancing, energy reporting and internal cost allocation — and it is £300 cheaper per unit. MID is certified for billing. If you are deciding, the question is not how accurate you need to be; it is whether anyone will be invoiced on the basis of the number. If yes, MID. If no, CT saves real money across a multi-unit installation.
Metering is not payment
These are two separate things and they get conflated. MID metering makes the reading billable. A payment terminal is what takes the money — contactless card, from £335 for a Charge-M8 Sigma kiosk or £450 for a Nayax VPOS Media 4 Mini. Some chargers combine both: the Nayax EV Meter Pay at £1,320 has the terminal built into the unit. Others expect you to pair a metered charger with a separate terminal or handle billing through an OCPP back office. Work out which model you want before you buy either half.
Practical advice
Decide the commercial model first, then specify the hardware. Sites that start with free charging and later want to bill are the ones that end up replacing chargers, so if there is any realistic prospect of charging for energy within the life of the equipment, pay the few hundred pounds for MID now. It is far cheaper than the alternative.
For pay-per-use sites, see our guide to EV charging for car parks and retail. For blocks of flats and communal parking, see EV charging for landlords and flats. Or get in touch and we will help you specify it.