Understanding MID Metering — What It Is and Why It Matters
MID metering is legally required in the UK when billing for EV charging. It ensures accurate, tamper-proof measurement of electricity used. Hotels, businesses, apartment buildings, and holiday lets all need MID-certified meters to charge customers, guests, or residents legally.
What is a MID Meter?
You may have noticed us mention "integrated MID Metering" insome of our product descriptions. But what does that actually mean and why doesit matter to you?
MID stands for Measurement Instruments Directive. It's a Europeanstandard that ensures devices measuring electricity are accurate andtrustworthy. After Brexit, the UK kept MID as part of its own Weights andMeasures regulations, so it still applies here in the UK.
In simple terms, a MID meter is an independent, tamper-proof device builtinto an EV charger that guarantees you are only ever charged for theelectricity you actually use, and nothing more or less.
Why does this matter?
Without independent metering, an EV charger relies on its own internalelectronics to measure energy. So if any components inside the EV charger areslightly out of tolerance (which can happen with lower-quality parts) you couldend up being overcharged without ever knowing it.
The presence of a MID meter removes that risk entirely. Think of it as areferee: it’s a component that is independent of the charger manufacturer, it’scertified to a recognised standard and legally accountable for its accuracy.
You've already trusted this technology for years.
The pump at your local petrol station works on exactly the sameprinciple. Every litre of fuel is measured by a certified, independentlyverified meter so you know precisely what you're paying for. MID meteringbrings that same peace of mind to EV charging.
When you see "MID Metering" in a Simpson & Partnersproduct, you can trust that every penny you're billed is correct.
Are You Selling Energy? Understanding Your Legal Obligations
In 2016, the Weights and Measures (Measuring Instruments) Regulationscame into effect. These regulations are clear: reselling electricity whether inhomes, apartment buildings, or through EV chargers is illegal withoutMID-approved metering.
So who does this affect, and could it apply to you?
Who Needs a MID Meter?
It’s probably easier to split this up into three charging sectors.
1. Destination Charging — Hotels, shopping and leisure facilities
Forward-thinking hospitality and retail businesses have recognised thatoffering EV charging is a brilliant way to improve the visitor experience andto create a useful additional revenue stream. When charging is billed by thekilowatt-hour, it's both fairer and more transparent than time-based billing.
However, most business owners in this sector have little awareness of EVregulations and the legal obligations that come with reselling energy. Chargingmanagement software makes it very easy to set up and start billing for EVcharging but easy to set up is not the same as legally compliant. Any businessbilling customers for charging without MID-certified meters is, unknowingly ornot, operating illegally.
2. Staff Charging — Offices, Factories and Schools
Many organisations have installed EV chargers for staff at theirworkplace a genuinely valuable benefit, particularly for employees who don'thave access to home charging.
Some organisations offer charging free of charge to staff, while othersrecover the cost by deducting it directly from employees' salaries. Where anemployer is billing staff for charging, MID metering is clearly required undercurrent regulations.
Looking ahead, even organisations offering free charging to employeeswill need to report usage to HMRC, as workplace charging is treated as ataxable benefit in kind. MID-certified meters will be essential for producingthe accurate usage records that reporting requires.
3. Residential Environments — Apartment Blocks and Holiday Homes
In apartment buildings where a management company bills residents for EVcharging, and in holiday rental properties where hosts charge guests, MIDmetering is a legal requirement. This is an area where compliance is stillwidely overlooked.
What Does a MID Meter Actually Look Like?
A MID meter is a small electronic measuring device. The technology insideis similar to the energy measurement electronics found in many EV chargers. Thecritical difference is that a MID meter's components have been independentlytested and certified in an approved laboratory, guaranteeing their measurementaccuracy under all conditions.
MID meters can be installed as a separate unit within an EV chargingpost, or as is increasingly the case integrated directly inside the chargeritself.
At Simpson & Partners, our earlier Business Charger models weredelivered with an optional MID meter installed within the plinth post. In 2026,our engineering team took this a step further: MID metering is now fullyintegrated inside our charger core modules across both our Business Plinth andWallbox ranges, including models designed for the holiday park and hospitalitysectors.
MID stands for Measurement Instruments Directive. It's a European standard that ensures devices measuring electricity are accurate and trustworthy. After Brexit, the UK retained MID as part of its own Weights and Measures regulations, so it continues to apply throughout the UK.
Yes. Under the 2016 Weights and Measures (Measuring Instruments) Regulations, reselling electricity — whether in homes, apartment buildings, workplaces, or through EV chargers — is illegal without MID approved metering. If you're billing anyone for the electricity they use to charge their vehicle, you must use a MID-certified meter.
If you're billing customers, guests, staff, or residents for EV charging by the kilowatt-hour (kWh), then yes — you legally need MID metering. This applies to:
· Hotels and hospitality venues charging guests for EV charging
· Shopping centres and leisure facilities billing customers
· Workplaces deducting charging costs from employee salaries
· Apartment buildings where management companies bill residents
· Holiday lets where hosts chargeguests for electricity used
Even if you're currently offering freecharging to employees, you'll need MID metering to produce accurate usagerecords for HMRC reporting, as workplace charging is treated as a taxable benefit in kind.
Operating without MID-certified metering when billing for electricity is illegal under UK Weights and Measures regulations. This applies whether you're aware of the requirement or not.
Beyond the legal risk, you're also exposing yourself to potential disputes with customers, guests, or residents who may question the accuracy of their billing. A MID meter provides legally defensible proof that your charging is accurate and fair.
It depends on your charger model. Some EV chargers can have a separate MID meter installed within the charging post or plinth. However, many older or basic chargers weren't designed with MID metering in mind, making retrofitting difficult or impossible.
Simpson & Partners' latest Business andHoliday Series chargers have MID metering fully integrated inside the chargercore from the factory, ensuring compliance from day one without any additionalinstallation complexity.
A separate MID meter is installed as an additional component within an EV charging post or enclosure. It functions correctly but adds complexity to installation and servicing.
An integrated MID meter is built directly into the charger's internal electronics during manufacturing.This is the modern approach used in Simpson & Partners' current range —it's neater, more reliable, and ensures every charger leaves the factory ready for legal, compliant billing.
Look for "MID metering" or"MID-certified" in the product specifications. Reputablemanufacturers will clearly state whether their chargers include MID metering asstandard, as an option, or not at all.
All Simpson & Partners Business Series and Holiday Series chargers include integrated MID metering as standard — it's not an optional extra. You can trust that you're getting a legally compliantsolution from the start.
No. Smart metering refersto the ability to remotely monitor and manage charging (often via an app orsoftware platform). MID metering refers specifically to thecertified, independent measurement of electricity for billing purposes.
A charger can be "smart" without being MID-certified, which means it might offer fancy features but still leaveyou operating illegally if you're billing for charging. Conversely, a MID-certified charger ensures accurate, legal billing — and many modern MID chargers (including Simpson & Partners models) are also smart, giving youboth compliance and convenience.
Currently, if you're offering completelyfree EV charging with no reimbursement or salary deduction, MID metering isn'tstrictly required. However, there are two important considerations:
1. Future-proofing: If you ever decide tostart billing for charging, you'll need MID metering. Installing it from thestart avoids costly upgrades later.
2. HMRC reporting: Workplace charging isa taxable benefit in kind. Even if you're not charging employees, you'll needaccurate usage records for tax reporting — and MID meters provide the legally defensible data HMRC requires.
For these reasons, many forward-thinking organisations are installing MID-certified chargers regardless of their current billing model and futureproofing their investments.
Simpson & Partners offers a completerange of EV chargers with integrated MID metering:
Business Series— For workplaces, car parks, and destination charging
Holiday Series — Purpose-built for holidaylets and hospitality
All include MID metering as standard, not asan optional extra. You get legal compliance, accurate billing, and peace ofmind from day one.
Get in touch:
📧sales@simpson-partners.com
📞01285 405 410
🌐simpson-partners.com
